Transparent optical component for light emitting/receiving elements

ABSTRACT

This invention improves the use efficiency of light emitted by a solid light emitter such as a light emitting diode, and realizes a desired directional pattern. On a front boundary surface of a mold resin  13  sealing a light emitter  12 , there are formed a direct emission region  18  for emitting the light from the light emitter  12  and a total reflection region  19  for totally reflecting the light from the light emitter  12 . The direct emission region  18  is convex lens-shaped. A light reflecting portion  20  having a concave mirror shape is disposed on a rear wall of the mold resin  13 . A part of light emitted from the light emitter  12  is emitted forward by receiving an optical lens action when it passes through the direct emission region  18 . Another part of the light emitted by from the light emitter  12  is totally reflected by the total reflection region  19 , and is reflected by the light reflecting portion  20 , and emitted forward from the total reflection region  19.

BACKGROUND OF THE INVENTION

This invention relates to an optical device and an apparatus employingthe optical device.

(Light Emission Source)

In a conventional light emission source in which a light emitting diodeis sealed in a mold resin, light emitted from the light emitting diodeto its front is emitted from the light emission source as it is, butlight emitted in a diagonal direction from the light emitting diode istotally reflected on a boundary surface of the mold resin and scatteredin an inside wall of a housing to be lost, resulting into deteriorationof use efficiency of light.

Heretofore, there has been proposed a light emission source capable ofefficiently emitting the light emitted in a diagonal direction which isdisclosed in the Japanese Laid-Open Patent Publication No. Hei 1-143368.FIG. 1 shows a sectional side view of a light emission source includinga light emitting diode 1, a transparent glass substrate 2, lead frames 3and 4, a bonding wire 5, a light reflecting member 6, and a mold resin 8made of an optically transparent resin. The lead frames 3 and 4 aredisposed on a rear wall of the transparent glass substrate 2, and thelight emitting diode 1 is mounted on a rear wall of the lead frame 3 tobe connected with the lead frame 4 by the bonding wire 5. A lightreflecting wall 7 of the light reflecting member 6 is formed as apolyhedron by plural monotonous surfaces.

In this conventional light emission source, light is emitted backsidefrom the light emitting diode 1 to be reflected by the reflecting wall 7and emitted forward through the mold resin 8 and the transparent glasssubstrate 2. In particular, light emitted from the light emitting diode1 in a diagonal direction is reflected back by the reflection wall 7 tobe emitted forward through the mold resin 8 and the transparent glasssubstrate 2, thereby improving the light use efficiency.

This conventional light emission source, however, has the disadvantagethat light reflected by the light reflecting member is obstructed by thelight emitting diode and the lead frames when it is emitted forward,thereby producing shadows of these components and deteriorating theadvantage of utilization of light near the optical axis center wherequantity of light should be provided most well. Furthermore, because ofdarkness near the optical axis center in the directional pattern oflight emitted by the light emission source, its appearance is bad as alight source for a display, and its visual performance also is bad.

FIG. 2 shows a side sectional view of conventional another lightemission source, wherein a light emitting diode 1 such as an LED chip isdie-bonded on a leading edge of one lead frame 3 to be connected withanother lead frame 4 by means of a bonding wire 5, which is sealed in atransparent mold resin 8. On a central part of a front wall (resinboundary surface) of the mold resin 8, there is disposed a lens portion9 so as to agree with an optical axis of the light emitting diode 1.

In this conventional light emission source of FIG. 2, the light emittingdiode 1 is not positioned behind the lead frame 3, and light emittedfrom the light emitting diode 1 is emitted forward from the lens portion9 without any obstruction.

In this conventional light emission source, however, only light emittedfrom the light emitting diode 1 to its front is used for externalemission, thereby decreasing the use efficiency of light. Moreover, justone light emission source becomes so-called point light source, so thatthe light emission area cannot be enlarged.

(Photo Detector)

For example, a photodiode serving as a sensor is improved about itssensitivity as the light requirement is increased, and a photoelectrictransducer increases an electric energy as the light requirement isincreased. Accordingly, it is desirable in these photo detectors toincrease the light requirement as far as possible.

In order to increase the light requirement when the intensity ofincident light is the same, it is an approach to increase the lightreceiving area of the photo detector. However, this approach to increasethe chip area of the photo detector reduces the number of chips whichcan be taken from one piece of monocrystal wafer, resulting into largeincrease of the manufacturing cost.

Moreover, it is another approach to dispose an optical lens ahead of aphoto detector to condense the light striking against the lens to thephoto detector. This photo detector needs a large optical lens, and thethickness is increased by the spacing between the photo detector and thelens, whereby the element becomes a large-scale.

SUMMARY OF THE INVENTION

It is, therefore, a first object of this invention to provide an opticaldevice such as a light emission source or a light receiver provided witha desired directional pattern.

It is a second object of this invention to improve the use efficiency ofthe light emitted from a solid light emitter such as a light emittingdiode.

It is a third object of this invention to increase a light emission areaof the light emitted from a solid light emitter such as a light emittingdiode.

It is a fourth object of this invention to raise the light receivingefficiency of a photo diode or a photoelectric transducer by making thelight receiving area big.

It is a fifth object of this invention to raise the assembly accuracy ofa light emission source and a light receiver and make the manufacturingeasy.

It is a sixth object of this invention to suppress degradation of thevisual performance of a light emission source or a component employingthe same when it is viewed from a lower part thereof (for example,ground) by disturbance light.

A first optical device according to this invention includes an opticalelement, a resin boundary surface for almost totally reflecting lightdeviated from a predetermined front area of the optical element, and alight reflecting member, in which the optical element, the resinboundary surface and the light reflecting member are positioned so thata light path from the optical element to the external of the opticaldevice can reflect back at least more than once with each of the resinboundary surface and the light reflecting member. The optical element isrepresented by a light emitter such as a light emitting diode, or aphoto detector such as a photo diode or a photoelectric transducer.According to this optical device, the light deviated from thepredetermined area is reflected by the resin boundary surface and thelight reflecting member in the light path between the optical elementand the front of the optical device, whereby a desired directionalpattern may be realized by the configuration of the resin boundarysurface and the light reflecting member, and the optical device may bethinned.

In a first light emission source according to this invention, a lightemitter is positioned to be covered by a resin so that the lightdeviated from a predetermined front area in the light emitted from thelight emitter is almost totally reflected by a resin boundary surface,and a light reflecting member is disposed behind the resin boundarysurface so as to reflect the light emitted from the light emitter andalmost totally reflected by the resin boundary surface to be emittedforward. The resin boundary surface almost totally reflecting the lightmay be a boundary surface between the resin and air or between the resinand other resin or a multilayer light reflecting film.

In this first light emission source, the light almost totally reflectedby the resin covering the light emitter is reflected by the lightreflecting member to be emitted forwardly, thereby improving the useefficiency of light. The light directly emitted forward by the lightemitter can be emitted forward without any obstruction by the lightemitter itself, thereby further improving the use efficiency of lightand the directional pattern without darkening a center of light emissionsource. Moreover, the directive pattern of the light emitted from thelight emission source may be optionally varied by changing theconfiguration of the resin boundary surface and the light reflectingmember.

According to a first aspect of the first light emission source, at leasta part of the resin boundary surface slants against a planeperpendicular to an optical axis of the light emitter in an areacontacting with the above-mentioned predetermined area. In the lightemission source of the first aspect, most of the light beams emittedfrom the light emitter to the boundary of the resin boundary surface andthe predetermined area make angles with the optical axis smaller thanthe critical angles of total reflection of the light reaching the resinboundary surface. By making the angle between the light reaching theboundary of the resin boundary surface from the light emitter and theoptical axis of the light emitter smaller than the critical angle of thetotal reflection, the light emitted from the light emitter by a smallerangle against the optical axis than the critical angle of the totalreflection in the resin boundary surface is totally reflected by theresin boundary surface and further reflected forward by the lightreflecting member. As a result, the ratio of stray light in thepredetermined area in a front of the light emitter is reduced and theuse efficiency of light is improved. All light emitted from the lightemitter to the boundary of the resin boundary surface and thepredetermined area is not always necessary to have an angle to theoptical axis smaller than the critical angle of the total reflection oflight reaching the resin boundary surface. As far as the angles of mostof light beams to the optical axis are smaller than the critical angleof total reflection of light reaching the resin boundary surface, suchan effect can be expected.

According to a second aspect of the first light emission source, atleast a region of the light reflecting member reached by the lighttotally reflected by the resin boundary surface constitutes a concavemirror having a focal point at a mirror position of the light emitterwith respect to the resin boundary surface. According to the lightemission source of this second aspect, the light reflected by the lightreflecting member is emitted forward as approximately paralleled light.

According to a third aspect of the first light emission source,distribution field of curvature in the light reflecting surfaces oflight reflecting member is different on a pair of mutually perpendicularsections crossing the optical axis of the light emitter. The differenceof distribution field of curvature means that the distribution fields ofcurvature are not the same, and includes the cases that the distributionfields are not mutually overlapped, the distribution fields arepartially overlapped but mutually shifted, or one distribution field iswider than another distribution field.

According to the light emission source of the third aspect, because ofdifference in the distribution fields of curvature in light reflectingplane of the light reflecting member on the mutually perpendicular twosections passing the optical axis of the light emitter, spread of thelight reflected by the light reflecting surface varies with itsdirection even if light emitted from the light emitter is emittedequally in a circumference of the optical axis. For instance, there maybe provided a light emission source having an asymmetry directionalpattern in a circumference of the optical axis, such as a directionalpattern spreading sideways, depending on application.

According to a fourth aspect of the light emission source of the thirdaspect, an optical lens disposed in a predetermined area in front of thelight emitter, and the distribution fields of curvature on a surface ofthe optical lens are different on mutually perpendicular sectionscrossing the optical axis of the light emitter. The difference ofdistribution field of curvature has same meaning in the light reflectingmember. According to the light emission source of the fourth aspect, theoptical lens condenses the light emitted forward. Since the lens has anasymmetry configuration around the optical axis, the light emittedforward from the light emitter through the lens has a symmetry orununiform directive pattern around the optical axis. Accordingly, forexample, the light emitted forward from a center of the light emittermay be spread sideways on application.

In a second light emission source of this invention including a lightemission face in front of a light emitter, the light emission faceinclines from a plane perpendicular to the optical axis of the lightemitter, whereby disturbance light reflected by the light emission facecan be avoided from going in the same direction as that of the lightemitted from the light emission source by selecting direction of thelight emission face. Accordingly, the light emission source is preventedfrom hindrance or invisible illumination by the disturbance lightreflected by the light emission source.

In a third light emission source having a light emission face in frontof a light emitter according to this invention, the light emission faceis disposed to turn to the top than horizontal, and at least a part ofthe light emitted from the light emission face is emitted toward lowerpart. Since the light emission face is disposed to turn to the top thanhorizontal and at least a part of the light emitted from the lightemission face is emitted toward a lower part in this third lightemission source, disturbance light from low altitudes such as theafternoon sun or the morning sun is hard to be reflected back to thelower part even if an apparatus employing this light emission source,for example, a display unit is installed in a high location. On theother hand, since the light from the light emission source is emitteddownward, it can be avoided that the display is hard to be seen or thatlighting condition and lights-out condition are misunderstood bydisturbance light.

According to a fifth aspect of the first light emission source, a lightemitter is positioned to be covered by a resin so that light deviatedfrom a predetermined area of front in the light emitted from the lightemitter is almost totally reflected by a resin boundary surface, and alight reflecting member is positioned behind the resin boundary surfacefor reflecting the light emitted from the light emitter to be almosttotally reflected by the resin boundary surface, wherein the lightreflected by the light reflecting member is emitted slanting against theoptical axis of the light emitter. Since the light reflected by thelight reflecting member is emitted slanting against the optical axis ofthe light emitter, the light emission direction can be positioned in adirection different from an installation direction of the light emissionsource. Accordingly, by emitting light to a desired direction, forexample, downward, and installing the light emission source upward,disturbance light such as the afternoon sun or the morning sun isprevented from downward reflection by the light emission source. In thislight emission source, the light emitted in a direction having a largeangle to the optical axis is totally reflected by the resin boundarysurface and further reflected forward by the light reflecting member tobe emitted forward from the light emission source, thereby improving theuse efficiency of light.

According to a sixth aspect of the first light emission source, at leasta region of the light reflecting member reached by the light totallyreflected by the resin boundary surface constitutes a concave mirror,and a light emitter is disposed in a location deviated from a mirrorposition of the focal point of the concave mirror with respect to theresin boundary surface. The light can be emitted toward the optical axisdeclining against the front of the light emission source, therebyincreasing the degrees of freedom of directional pattern of the lightemission source.

According to a seventh aspect of the first light emission source, thereis provided a second light reflecting member reflecting the lightemitted from a side of the light emitter in a forward direction, inwhich the angle of inclination of the second light reflecting member isset so that most of light reflected by the second light reflectingmember can reach the resin boundary surface. The light emitted from theside of the light emitter is reflected by the second light reflectingmember to be directly emitted to the external from the predeterminedarea without emission in a direction largely declining from the opticalaxis of the light emission source. In other words, the light emittedfrom the side of the light emitter is reflected by the second lightreflecting member to be directed to the resin boundary surface, wherebythe light totally reflected by the resin boundary surface is directed tothe light reflecting member and its emission direction is controlled bythe light reflecting member so as to emit the light in the optical axialdirection of the light emission source.

According to an eighth aspect of the light emission source of theseventh aspect, the second light reflecting member is disposed on a leadframe mounted by the light emitter. When the light emitter is disposedon the lead frame, the second light reflecting member may be made by thelead frame, thereby reducing the number of components.

According to a ninth aspect of the first light emission source, at leasta part of the light reflecting member comes into contact with an outercircumferential part of the resin composing the resin boundary surface.When the light emission source is produced by resin molding, the lightreflecting member can be positioned by hitting an internal circumferencepart of a metal mold cavity and a location accuracy of the lightreflecting member can be easily obtained.

In an light receiver molding a photo detector within a resin accordingto this invention, a light reflecting member is disposed behind aboundary surface on a light receiving side of the resin so that itreflects the light entering into a region deviated from a predeterminedarea in front of the photodetector to be totally reflected by a resinboundary surface to be received by the photo detector.

In this light receiver, the light entering into an outside of the photodetector is reflected by the light reflecting member to enter into thephoto detector after total reflection by the resin boundary surface,whereby the light receiving area of the light receiver is increasedwithout increasing the area of the photo detector, thereby improving thelight receiving efficiency of the light receiver. Moreover, light isgathered by the light reflecting member located behind the boundarysurface on the light receiving side of the resin and the resin boundarysurface, whereby the light receiver can have a relatively thinnedconfiguration.

According to a first aspect of the light receiver, at least a part ofthe light reflecting member of the light receiver comes into contactwith the outer circumferential part of the resin layer composing theresin boundary surface. According to the light receiver of the firstaspect, when the light receiver is produced by resin molding, the lightreflecting member can be positioned by hitting an internal circumferencepart of a metal mold cavity and a location accuracy of the lightreflecting member can be easily obtained.

A first optical component according to this invention is an opticalmodule in which a light active element such as a light emitter or aphoto detector is mounted on an element mounting position, whichincludes a resin boundary surface for almost totally reflecting thelight deviated from a predetermined area in front of the elementmounting position and a light reflecting member. The element mountingposition, the resin boundary surface and the light reflecting member arepositioned so that a light path from the element mounting position tothe external may pass a path which at least reflects back more than oncewith each of the resin boundary surface and the light reflecting member.The light active element is represented by a solid light emission chipsuch as an LED (light emitting diode) chip, a light emitter packaging anLED chip, a photo diode, a photo-transistor, or a photoelectrictransducer (solar battery cell). The light path from the elementmounting position to the external includes a light path from the lightactive element mounted on the element mounting position to an externalof the light active element and the optical module or a light pathentering from the external of the light active element and the opticalmodule into the light active element mounted on the element mountingposition.

In thus optical component, light emitted from the light active elementsuch as a light emitter in a direction deviating from a predeterminedarea is totally reflected by a resin boundary surface, and furtherreflected by the light reflecting member to be externally emitted,whereby a desired directive pattern can be obtained by designingconfigurations of the resin boundary surface and the light reflectingmember. As the light entering from the external is reflected by thelight reflecting member, the light emitted in a direction deviating fromthe predetermined area is totally reflected by the resin boundarysurface to enter into the light active element such as a photo detector,whereby desired light receive characteristics can be obtained bydesigning configurations of the resin boundary surface and the lightreflecting member. Moreover, the optical component can be miniaturizedand thinned by reflecting back the light with the resin boundary surfaceand the light reflecting member.

A second optical component according to this invention to be positionedon a front of a light source includes a resin boundary surface foralmost totally reflecting the light emitted from the light source and alight reflecting member for reflecting the light almost totallyreflected by the resin boundary surface to be emitted forward. Accordingto the second optical component, functions and effects same as theabove-mentioned first light emission source can be performed bycombining with the light emitter. This optical component is a separatecomponent from the light emitter, whereby its handling is easy becauseit may be later mounted on the light emitter. This optical component mayprovide same functions and effects when it is applied to a light sourcesuch as an electric lamp or a fluorescent lamp in addition to the lightemitter.

A third optical component according to this invention, which ispositioned on a front of a photo detector, includes a light reflectingmember for reflecting the light entering from an external and a resinboundary surface for totally reflecting the light reflected by the lightreflecting member to strike against the photo detector. According to thethird optical component, functions and effects same as theabove-mentioned light receiver can be performed by combining with thephoto detector. This optical component is separate from the photodetector, whereby its handling is easy because it may be later mountedon the photo detector.

According to a first aspect of each of the first, second and thirdoptical components, the optical component includes a recess on anopposite face of each component against the resin boundary surface inorder to at least dispose either the light emitter or the photodetector. According to the optical component of the first aspect, thelight emitter or the photo detector is disposed within the recess,whereby the light emitter, the photo detector or the optical componentcan be easily positioned.

According to a second aspect of each of the first, second and thirdoptical components, the optical component includes an engagement portionin order to establish a positional relationship with the opticallyactive element in the element mounting position. The engagement means acomplete contact without any spacing. According to this second aspect,since the optical component includes the engagement portion, theoptically active element can be mounted without any chattering, and theoptical component can be easily positioned with the optically activeelement.

According to a third aspect of each of the first, second and thirdoptical components, a recess or an open hole is disposed in the positionof the element mounting position to enclose or be inserted by theoptically active element, whereby the optical component can bethree-dimensionally combined with the optically active element toprovide a miniaturized construction.

According to a fourth aspect of each of the first, second and thirdoptical components, there is disposed a positioning portion to fix apositional relationship with the optically active element. Accordingly,when the optical component is combined with an optically active element,both members can be positioned by the positioning portion and combinedwithout any chattering, and mutual optical-axis alignment of the memberscan be easily performed.

According to a fifth aspect of each of the first, second and thirdoptical components, an external configuration of the component viewedfrom its front includes a major axial direction and a minor axialdirection. According to this optical component, for instance, when lightemitted from a light emitter is reflected by the optical component to beemitted forward, the light includes a major axial direction and a minoraxial direction, in other words, light having an oval light flux sectionis emitted.

An optical component array in accordance with this invention includes aplurality of the optical components arranged in a desired fashion so asto provide a flat light source. Each optical component can beminiaturized, whereby each light emission point can be minutely made andthe optical component array can be thinned.

A second optical device according to this invention includes anarrangement such that the above-mentioned optical component and theabove-mentioned optically active element are arranged by a predeterminedspacing which is filled with optically transparent materials so as toengage the optical component with the optically active element, wherebythe optical component and the optically active element are not necessaryto have any high dimensional accuracies and the optical component can beeasily manufactured.

According to a sixth aspect of each of the first, second and thirdoptical components, at least a part of the above-mentioned lightreflecting member comes into contact with an outer circumferential partof the resin layer providing the resin boundary surface. According tothe above-mentioned second aspect of each of the optical components,when the optical component is manufactured by a resin mold, the lightreflecting member is put on an internal circumference part of a cavityof a metal mold for fixing the position, thereby easily obtaining apositional accuracy of the light reflecting member.

A manufacturing process of the first optical component including a resinlayer having a resin boundary surface for almost totally reflecting thelight deviating from a predetermined region in front of a light emitterand a light reflecting member for forwardly emitting the light almosttotally reflected by the resin boundary surface according to thisinvention is provided with a process for resin-injecting at least a partof an outer circumferential part of the light reflecting member strikingagainst an internal surface of a cavity of a metal mold.

According to the manufacturing process of the first optical component ofthis invention, the first optical component can be produced, and thelight reflecting member strikes against an internal circumferential partof the cavity of the metal mold for fixing the position, thereby easilyobtaining a positional accuracy of the light reflecting member.

A manufacturing process of the second optical component including alight reflecting member for reflecting the light entering into a regiondeviating from a predetermined region in front of a photo detector and aresin layer having a resin boundary surface for almost totallyreflecting the light reflected by the light reflecting member accordingto this invention is provided with a process for resin-injecting atleast a part of an outer circumferential part of the light reflectingmember striking against an internal surface of a cavity of a metal mold.

According to the manufacturing process of the second optical componentof this invention, the second optical component can be produced, and thelight reflecting member strikes against an internal circumferential partof the cavity of the metal mold for fixing the position, thereby easilyobtaining a positional accuracy of the light reflecting member.

In a light emission method according to this invention, the lightdeviated from a predetermined front area among the light emitted from alight source is almost totally reflected by a resin boundary surface,and the light totally reflected by the resin boundary surface is emittedforward by the light reflecting member disposed behind the resinboundary surface. According to this light emission method, the lightdeviated from the predetermined area is reflected by the resin boundarysurface and the light reflecting member in a light path emitted from thelight source, thereby realizing a desired directional pattern by theconfigurations of the resin boundary surface and the light reflectingmember.

In a light incidence method according to this invention, the lightdeviated from a predetermined area in front of a photo detector amongthe light entered from an external is almost totally reflected by alight reflecting member, and the light reflected by the light reflectingmember is totally reflected by a resin boundary surface to strikeagainst the photo detector. According to this light incidence method,the light deviated from the predetermined area is reflected by the resinboundary surface and the light reflecting member in a light pathentering into the photo detector, thereby realizing a desireddirectional pattern by the configurations of the resin boundary surfaceand the light reflecting member.

The light emission source and the light receiver according to thisinvention can be applied to various kinds of apparatuses. For example,the photoelectric sensor according to this invention includes the lightreceiver employing a photoelectric transducer as a photo detectoraccording to this invention and a light projecting element, in which thelight emitted by the light projecting element or the light emitted bythe light projecting element and reflected by an object is detected bythe light receiver. A self light generating apparatus according to thisinvention includes the light receiver employing a photoelectrictransducer as the photo detector according to this invention, a batterycharger for charging electric energies generated by the light receiver,and a light receiver. A display apparatus according to this invention isarranged by a plurality of light emission sources according to thisinvention or a plurality of optical components according to thisinvention. A light source for an automobile lamp according to thisinvention is arranged by a plurality of light emission sources accordingto this invention or a plurality of optical components according to thisinvention. An outdoor display apparatus according to this invention isarranged by a plurality of light emission sources according to thisinvention or a plurality of optical components according to thisinvention.

The above-mentioned components of construction can be optionallycombined as far as possible.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a conventional light emission source;

FIG. 2 is a sectional view of another conventional light emissionsource;

FIG. 3 is a sectional view of a light emission source according to afirst embodiment of this invention;

FIG. 4 shows at (a) the light emission source of FIG. 3 and a lightquantity distribution of the same, and at (b) a light quantitydistribution of a conventional light emission source;

FIG. 5 is a sectional view of a light emission source according to asecond embodiment of this invention;

FIG. 6 is a sectional view of a light emission source according to athird embodiment of this invention;

FIG. 7 is a sectional view of a light emission source according to afourth embodiment of this invention;

FIG. 8 is a sectional view of a light emission source according to afifth embodiment of this invention;

FIG. 9 is a perspective view of a mold resin employed in the lightemission source of FIG. 8;

FIG. 10 is a sectional view of the light emission source of FIG. 8;

FIG. 11 is a magnified view of a portion A of FIG. 8;

FIG. 12 is a sectional view of a light emission source according to asixth embodiment of this invention;

FIG. 13 is a sectional view of a light emission source according to aseventh embodiment of this invention;

FIG. 14 is a sectional view of a light emission source according to aneighth embodiment of this invention;

FIG. 15 is a sectional view of a light emission source according to aninth embodiment of this invention;

FIG. 16 is a sectional view of a light emission source according to atenth embodiment of this invention;

FIG. 17 is a sectional view of a light emission source according to aneleventh embodiment of this invention;

FIG. 18 is a sectional view of a light emission source according to atwelfth embodiment of this invention;

FIG. 19 is a sectional view of a light emission source according to athirteenth embodiment of this invention;

FIG. 20 is a sectional view of a light emission source according to afourteenth embodiment of this invention;

FIG. 21 is a sectional view of a light emission source according to afifteenth embodiment of this invention;

FIG. 22 shows color splitting in a conventional light emission source ina two chip-shape

FIG. 23 is a sectional view of a light emission source according to asixteenth embodiment of this invention;

FIG. 24 is a sectional view of a light emission source according to aseventeenth embodiment of this invention;

FIG. 25 shows at (a) a front enlarged view of a lead frame employed inthe light emission source of FIG. 24, and at (b) a partially broken sideview of the same;

FIG. 26 is an enlarged sectional side view of a portion of FIG. 24 toexpress light movement;

FIG. 27 is a sectional view showing an embodiment to be compared withthe embodiment of FIG. 24;

FIG. 28 is a view showing light movement in the embodiment of FIG. 27;

FIG. 29 is a sectional view of a light emission source according to aneighteenth embodiment of this invention;

FIG. 30 is a perspective view of a light receiver according to anineteenth embodiment of this invention;

FIG. 31 is a sectional view of the light receiver of FIG. 30;

FIG. 32 is a sectional view of a light receiver according to a twentiethembodiment of this invention;

FIG. 33 is a perspective view of a light receiver according to atwenty-first embodiment of this invention;

FIG. 34 is a perspective view of a light receiver according to atwenty-second embodiment of this invention;

FIG. 35 shows at (a) a front view of the light emission source of FIG.34, at (b) a sectional view taken along line X1-X1 of FIG. 35 at (a),and at (c) a sectional view taken along line Y1-Y1 of FIG. 35 at (a);

FIG. 36 shows a profile of light beams emitted by the light emissionsource of FIG. 34;

FIG. 37 shows an intensity distribution of light emitted by the lightemission source of FIG. 34;

FIG. 38 shows at (a) a perspective view of a light reflection portionhaving a biconical surface, and at (b) a relationship between thebiconical surface and the coordinate;

FIG. 39 shows at (a) a front view of a light emission source accordingto a twenty-third embodiment of this invention, at (b) a sectional viewtaken along line X2-X2 of FIG. 39 at (a), and at (c) a sectional viewtaken along line Y2-Y2 of FIG. 39 at (a);

FIG. 40 shows a profile of light beams emitted by the light emissionsource of FIG. 39;

FIG. 41 shows at (a) a front view of a light emission source accordingto a twenty-fourth embodiment of this invention, at (b) a sectional viewtaken along line X3-X3 of FIG. 41 at (a), and at (c) a sectional viewtaken along line Y3-Y3 of FIG. 41 at (a);

FIG. 42 shows a profile of light beams emitted by the light emissionsource of FIG. 41;

FIG. 43 shows at (a) a front view of a light emission source accordingto a twenty-fifth embodiment of this invention, at (b) a sectional viewtaken along line X4-X4 of FIG. 43 at (a), and at (c) a sectional viewtaken along line Y4-Y4 of FIG. 43 at (a);

FIG. 44 shows at (a) a front view of a light emission source as amodification of the twenty-fifth embodiment, at (b) a sectional viewtaken along line X5-X5 of FIG. 44 at (a), and at (c) a sectional viewtaken along line Y5-Y5 of FIG. 44 at (a);

FIG. 45 shows at (a) movements of light emitted at an edge of a resinboundary surface in a light emission source having no slant wall, and at(b) movements of light emitted at an edge of a resin boundary surface ina light emission source having a slant wall;

FIG. 46 shows at (a) a front view and at (b) a sectional view of a lightemission source according to a twenty-sixth embodiment of thisinvention;

FIG. 47 is a front view of a light emission source according to atwenty-seventh embodiment of this invention;

FIG. 48 is a front view of a light receiver according to a twenty-eighthembodiment of this invention;

FIG. 49 is a sectional view of the light receiver of FIG. 48;

FIG. 50 shows at (a) a front view and at (b) a perspective view of photodetectors which can be employed in the light receiver of FIG. 48;

FIG. 51 is a sectional view of a light emission source according to atwenty-ninth embodiment of this invention;

FIG. 52 is a sectional view of a light emission source according to athirtieth embodiment of this invention;

FIG. 53 is a sectional view of a light emission source according to athirty-first embodiment of this invention;

FIG. 54 shows an enlarged view of a portion of FIG. 53;

FIG. 55 is a sectional view of a light emission source according to athirty-second embodiment of this invention;

FIG. 56 shows an enlarged view of a portion of FIG. 55;

FIG. 57 shows at (a) a sectional view of a light emission sourceaccording to a thirty-third embodiment of this invention, and at (b) afront view of an optical module;

FIG. 58 is a sectional view of a light emission source according to athirty-fourth embodiment of this invention;

FIG. 59 is a sectional view of a light emission source according to athirty-fifth embodiment of this invention;

FIG. 60 is a sectional view of a light emission source according to athirty-sixth embodiment of this invention;

FIG. 61 is a sectional view of a light emission source according to athirty-seventh embodiment of this invention;

FIG. 62 is a sectional view of a light emission source according to athirty-eighth embodiment of this invention;

FIG. 63 is a sectional view of a light emission source according to athirty-ninth embodiment of this invention;

FIG. 64 is a sectional view of a light emission source according to afortieth embodiment of this invention;

FIG. 65 is a sectional view of a light emission source according to aforty-first embodiment of this invention;

FIG. 66 at (a) to (c) shows a manufacturing process for theabove-mentioned light emission source;

FIG. 67 shows a sectional view of a modification of the forty-firstembodiment;

FIG. 68 is a sectional view of a light emission source according to aforty-second embodiment of this invention;

FIG. 69 is a sectional view of a light emission source according to aforty-third embodiment of this invention;

FIG. 70 shows a sectional view of a modification of the forty-thirdembodiment;

FIG. 71 shows a sectional view of a modification of the forty-thirdembodiment;

FIG. 72 is a sectional view of a light emission source according to aforty-fourth embodiment of this invention;

FIG. 73 is a sectional view of a light receiver according to aforty-fifth embodiment of this invention;

FIG. 74 is a sectional view of a light receiver according to aforty-sixth embodiment of this invention;

FIG. 75 is a sectional view of a light emission source according to aforty-seventh embodiment of this invention;

FIG. 76 shows a sectional view of a modification of the forty-seventhembodiment;

FIG. 77 shows a sectional view of another modification of theforty-seventh embodiment;

FIG. 78 shows a sectional view of another modification of theforty-seventh embodiment;

FIG. 79 shows a sectional view of another modification of theforty-seventh embodiment;

FIG. 80 is a sectional view of a light emission source according to aforty-eighth embodiment of this invention;

FIG. 81 shows a manufacturing process for a light emission sourceaccording to a forty-ninth embodiment of this invention;

FIG. 82 is a perspective view of a light emission source array accordingto a fiftieth embodiment of this invention;

FIG. 83 is a sectional view of the above-mentioned light emission sourcearray;

FIG. 84 shows a sectional view of a modification of the fiftiethembodiment;

FIG. 85 shows an arrangement of light emission sources in a lightemission source array;

FIG. 86 shows an arrangement of light emission sources in a lightemission source array;

FIG. 87 shows an arrangement of light emission sources in a lightemission source array;

FIG. 88 shows an arrangement of light emission sources in a lightemission source array;

FIG. 89 at (a) and (b) shows sectional and front views of a constructionof a light emission source according to a fifty-first embodiment of thisinvention;

FIG. 90 at (a) and (b) shows sectional and front views of a constructionof the light reflection member employed in the light emission source ofFIG. 57;

FIG. 91 is an operation explanatory view of the light emission source ofFIG. 57;

FIG. 92 shows light distribution characteristics of the light emissionsource of FIG. 57;

FIG. 93 is a front view of a signal according to a fifty-secondembodiment of this invention;

FIG. 94 is a side view of the signal of FIG. 61;

FIG. 95 is a sectional view of a signal lamp providing the signal ofFIG. 61;

FIG. 96 shows a direction of light emitted from the signal of FIG. 61;

FIG. 97 is a sectional view of a comparative example of a signal lamp;

FIG. 98 is a front view of a light emission display apparatus accordingto a fifty-third embodiment of this invention;

FIG. 99 is a front view of a light emission display unit providing thedisplay apparatus of FIG. 66;

FIG. 100 is a side view of the light emission display unit of FIG. 67;

FIG. 101 is a side view a comparative example of alight emission displayunit;

FIG. 102 is a sectional view of a light emission source according to afifty-fourth embodiment of this invention;

FIG. 103 is a sectional view of a light emission source according to amodification of the fifty-fourth embodiment of this invention;

FIG. 104 is a sectional view of a light emission source according to afifty-fifth embodiment of this invention;

FIG. 105 is a sectional view of a light emission source according to amodification of the fifty-fifth embodiment of this invention;

FIG. 106 is a sectional view of a light emission source according to afifty-sixth embodiment of this invention;

FIG. 107 shows a different shape front of the light emission source;

FIG. 108 shows a further different shape front of the light emissionsource;

FIG. 109 shows a still further different shape front of the lightemission source;

FIG. 110 shows a still further different shape front of the lightemission source;

FIG. 111 is a sectional view of a light emission source according to afifty-seventh embodiment of this invention;

FIG. 112 is a sectional view of a light emission source according to amodification of the fifty-seventh embodiment of this invention;

FIG. 113 is a sectional view of a light emission source according to afifty-eighth embodiment of this invention;

FIG. 114 is a sectional view of a light emission source according to afifty-ninth embodiment of this invention;

FIG. 115 is a sectional view of alight emission source according to amodification of the fifty-ninth embodiment of this invention;

FIG. 116 is a sectional view of alight emission source according to asixtieth embodiment of this invention;

FIG. 117 is a sectional view of alight emission source according to amodification of the sixtieth embodiment of this invention;

FIG. 118 is a sectional view of a light emission source according to amodification of the fifty-fourth embodiment of this invention;

FIG. 119 is a sectional view of a light emission source according toanother modification of the fifty-fourth embodiment of this invention;

FIG. 120 is a sectional view of a light emission source according to asixty-first embodiment of this invention;

FIG. 121 shows front and side views of an outdoor display apparatusaccording to a sixty-second embodiment of this invention;

FIG. 122 is a side view of the outdoor display apparatus of FIG. 89(121) on use;

FIG. 123 shows a manufacturing process for a light emission sourceaccording to a sixty-third embodiment of this invention;

FIG. 124 is a perspective view of a light emission display according tosixty-fourth of this invention;

FIG. 125 shows at (a) a perspective view of a conventional lightemission source employed in a light emission display, and at (b) anarrangement of the light emission source;

FIG. 126 is a perspective view of an external configuration of a lightemission source employed in the light emission display of FIG. 92 (124);

FIG. 127 shows one picture element of a full color light emissiondisplay in which a red light emission source, a green light emissionsource, a blue light emission source are arranged in a delta fashion;

FIG. 128 is a schematic diagram showing an optical fiber coupleraccording to a sixty-fifth embodiment of this invention;

FIG. 129 is a schematic diagram showing a signal lamp according to asixty-sixth embodiment of this invention;

FIG. 130 is a schematic diagram showing an advertisement signboardaccording to a sixty-seventh embodiment of this invention;

FIG. 131 is a schematic diagram showing an advertisement signboardaccording to a modification of the sixty-seventh;

FIG. 132 is a perspective view of a high mount strap lamp according to asixty-eighth embodiment of this invention;

FIG. 133 is a perspective view of a single light emission sourceemployed in the high mount strap lamp of FIG. 100 (132);

FIG. 134 is a perspective view of a high mount strap according to asixty-ninth embodiment of this invention;

FIG. 135 is a perspective view of the high mount strap of FIG. 102 (134)installed into a car;

FIG. 136 shows at (a) an enlarged sectional view of a portion of thehigh mount strap of FIG. 102 (134), and at (b) a front view of the same;

FIG. 137 shows at (a) an enlarged sectional view of a portion of aconventional high mount strap, and at (b) a front view thereof;

FIG. 138 is a perspective view of a display apparatus according to aseventieth embodiment of this invention;

FIG. 139 is a perspective view showing a beam configuration of lightemitted from a light emission source employed in the display apparatusof FIG. 106 (138);

FIG. 140 is a perspective view showing an area where display by thedisplay apparatus of FIG. 106 (138) can be recognized;

FIG. 141 is a sectional view of a photoelectric sensor according to aseventy-first embodiment of this invention;

FIG. 142 is a sectional view of a road tack according to aseventy-second embodiment of this invention;

FIG. 143 is a perspective view of an illumination-type switch accordingto a seventy-third embodiment of this invention;

FIG. 144 is a disassembled perspective view of the illumination-typeswitch according of FIG. 111 (143);

FIG. 145 is a schematic sectional view of the illumination-type switchaccording of FIG. 111 (143); and

FIG. 146 is a schematic sectional view of a conventionalillumination-type switch.

DETAILED DESCRIPTION

Embodiments of this invention will be described in detail hereinafterreferring to drawings.

First Embodiment

As a first embodiment, a section of a light emission source 11 is shownin FIG. 3. According to this embodiment, a light emitter 12 of a lightemitting diode (LED chip) is sealed in a mold resin 13 made of opticallytransparent resin materials. The light emitter 12 sealed in the moldresin 13 is mounted on a stem 15 disposed on a leading edge of a leadframe 17, and connected with another lead frame 14 by a bonding wire 16so that a light emission side is disposed toward a front of the lightemission source 11.

In a front central part of the mold resin 13, there is disposed a directemission region 18 having a convex lens configuration such as aspherical lens shape, an aspherical lens shape, or a paraboloid shape. Atotal reflection region 19 in a flat shape is formed to surround thedirect emission region 18. The direct emission region 18 is formed sothat its medial axis can accord with medial axis of the light emitter12, and the total reflection region 19 is formed to be a flat planeperpendicular to an optical axis of the light emitter 12. The lightemitter 12 is located in focal point of the direct emission region 18 orthe neighborhood. The angle α of a direction, viewed from the lightemitter 12 to the boundary between the direct emission region 18 and thetotal reflection region 19, from the optical axis of the light emitter12 is equal to a critical angle θ c of total reflection between the moldresin 13 and air or larger.

Therefore, light emitted to the direct emission region 18 in the lightemitted from the light emitter 12 is emitted approximately in paralleldirectly from a front of the mold resin 13 to front. Light emitted tothe total reflection region 19 in the light emitted from the lightemitter 12 is totally reflected by its resin boundary surface to bedirected to a rear face of the mold resin 13.

The rear face of the mold resin 13 is coated with a metal film having ahigh reflectivity such as aluminum or silver by vacuum deposition or amultilayer reflection film to provide a light reflection portion 20. Atleast a region of the light reflection portion 20 hit by the lightreflected by the total reflection region 19 provides a concave mirror,such as a spherical mirror or revolution-parabolic mirror, having afocal point around a mirror position of the light emitter 12 withrespect to the total reflection region 19.

Accordingly, light emitted from the light emitter 12 and totallyreflected by the total reflection area 19 strikes against the lightreflection portion 20 to be reflected thereby and emitted forward fromthe total reflection region 19 in approximately parallel.

Therefore, according to the light emission source 11 of this embodiment,approximately all light forwardly emitted from the light emitter 12(including the light totally reflected by the total reflection region19) can be taken toward a forward direction of the light emission source11, resulting into high efficiency of light use. Moreover, the lightemitted forward from the light emitter 12 can be emitted from the directemission region 18 without any obstruction, whereby darkness on theoptical axis as found in a conventional light emission source can beavoided and the directional pattern also can be improved.

Furthermore, the light emitted from the light emitter 12 in a diagonaldirection is totally reflected by the total reflection region 19 andfurther reflected by the light reflection portion 20 for forwardemission, whereby the optical path length is elongated, thereby reducingits aberration and providing a high accuracy of the light emissionsource 11.

In a conventional light emission source employing a light emittingdiode, most of light totally reflected by a mold resin is not emittedforward, thereby providing a narrow distribution about quantity of lightas shown in FIG. 4 at (b). As shown in FIG. 4 at (a), according to thelight emission source 11 of this embodiment, the light emitted from thelight emitter 12 is spread over a whole front face of the mold resin 13and approximately paralleled, thereby providing a width-wide and uniformdistribution of light quantity (beam profile).

In this embodiment, the light emission source is designed to emit theparalleled light. If desired, the directional pattern of the lightemitted from the light emitter 11 can be changed to a desired pattern bychanging the position of the light emitter 12, the focal position andthe surface configuration of the direct emission region 18 providing aconvex lens, or the focal position and the surface configuration of thelight reflection portion 20 providing a concave mirror.

Second Embodiment

FIG. 5 shows a sectional view of a light emission source 21 according toa second embodiment. FIG. 5 omits the components of a stem, a leadframe, and a bonding wire (delineation of lead frame and others might beomitted in a light emission source shown in FIG. 6 and its subsequentfigures). In this embodiment, a direct emission region 18 in a boundarysurface of a mold resin 13 is formed to be flat. Accordingly, directemission region 18 and total reflection region 19 cannot bedistinguished from their appearance, but can be distinguished by themovement of light beams emitted from a light emitter 12. The position ofthe light striking against a boundary surface of the mold resin 13 fromthe light emitter 12 at a critical angle θ c of its total reflectionbecomes a boundary of the direct emission region 18 and the totalreflection boundary 19. Therefore, the incident light striking againstthe direct emission region 18 inside of the boundary is directly emittedfrom the direct emission region 18, and the light striking against thetotal reflection region 19 outside of the boundary is totally reflectedby the total reflection region 19 to be reflected by a light reflectionportion 20 for forward emission.

In this embodiment, total reflection is made by the boundary surface ofthe mold resin 13, and the efficiency of light use is improved also. Thedirect emission region 18 is formed to be plane, whereby the lightemitted from the direct emission region 18 is spread and the angle ofbeam spread of light emitted from the region can be broadly widened.When the angle of beam spread is desired to be widened or the limitationto the angle is minor, the direct emission region 18 can be formed to beflat so as to simplify the front configuration of the mold resin 13 likethis embodiment.

Third Embodiment

FIG. 6 is a sectional view of a light emission source 22 according to athird embodiment, in which a front portion 18 a of a direct emissionregion 18 is formed to be larger than a base portion 18 b and to providea lens configuration. When the light totally reflected by a resinboundary surface and further reflected by a light reflection portion 20is approximately paralleled, a region where any light is not emittedappears in an internal circumference portion of a total reflectionregion 19, so that the lens configuration of the direct emission region18 can have a large diameter without narrowing the total reflectionregion 19 by enlarging the front portion 18 a of the direct emissionregion 18 as far as light emitted from the total reflection region 19 isnot obstructed. According to this configuration, the ratio of the lightemitted from the direct emission region 18 of a lens configuration andthe light emitted from the total reflection region 19 can be efficientlydesigned, thereby providing a high performance of the light emissionsource 22.

Fourth Embodiment

In the light emission source 11 shown in FIG. 3, the light strikingagainst an edge (outer circumferential portion) of the direct emissionregion 18 is blocked so that it cannot be emitted forward, whereby theblocked light emitted from the light emitter 12 becomes loss. When thedistance between the light emitter 12 and the direct emission region 18is short, the curvature of the direct emission region 18 becomes large,whereby the light emitted to the edge of the direct emission region 18can be emitted in a traverse direction or totally reflected. Moreover,the edge of the direct emission region 18 has to be positioned outsideof a direction of an angle from the medial axis of the light emitter 12which is equal to the critical angle of total reflection, so thatbecause of a lower limit in the dimension (diameter viewed from thefront) of the direct emission region, area of the circumference part ofthe direct emission region 18 becomes large and loss of light emittedfrom the light emitter 12 becomes large. Moreover, because of a lowerlimit in the dimension of the direct emission region 18, the curvatureof a surface of the direct emission region 18 also has an upper limitand the design flexibility of the direct emission region 18 is limited.

In view of the above, FIG. 7 shows a sectional view of a light emissionsource 23 according to a fourth embodiment, in which a direct emissionregion 18 is disposed in the center of a surface of a mold resin 13 anda total reflection region 19 is disposed outside its circumference. Thedirect emission region 18 has a generally hemispheric shape, and itsmedial axis accords with an optical axis C of light emitter 12. In thelight emission source 23, the light emitted from the light emitter 12toward the direct emission region 18 is refracted-and emittedapproximately forward from the direct emission region 18.

The total reflection region 19 is composed of a taper-shaped portion 19b in a conical (block) shape or a pyramid (block) shape, and a flatportion 19 a, wherein a medial axis of the taper-shaped portion 19 bagrees with an optical axis C of the light emitter 12, and the flatportion 19 a has a face perpendicular to the optical axis C of the lightemitter 12. The section of the taper-shaped portion 19 b passing themedial axis is straight but may be curve. For example, the taper-shapedportion 19 b may be a surface of revolution of curve with a rotationaxis representing the medial axis.

The angle θ b of a direction, which is viewed from the light emitter 12to a boundary between the flat portion 19 a and the taper-shaped portion19 b, from the optical axis C of the light emitter 12 is designed to belarger than the critical angle θ c of the total reflection in theboundary surface of the mold resin 13 (for example, against air).Therefore, all light emitted from the light emitter 12 and strikingagainst the flat portion 19 a is reflected by the flat portion 19 a soas to be directed to a light reflecting portion 20.

In addition, the angle θ a of the direction, which is viewed from thelight emitter 12 to an edge of the direct emission region 18 (theboundary between the direct emission region 18 and the taper-shapedportion 19 b), from the optical axis C of the light emitter 12 isdesigned to be smaller than the critical angle θ c of the totalreflection in the boundary surface of the mold resin 13 (for example,against air). In other words, when viewed from a front, the dimension ofthe direct emission region 18 is smaller, and the sharing ratio of theoutré circumferential part of the direct emission region 18 against theall is smaller, in comparison with the light emission source 11 shown inFIG. 3. Accordingly, the light lost by the sideway emission at an edgeof the direct emission region 18 or total reflection in the lightemission source shown in FIG. 3 is totally reflected by the taper-shapedportion 19 b and reflected by the light reflecting portion 20 to beemitted forward, thereby decreasing the loss of light. Since the directemission region 18 is small, the curvature in the surface of the directemission region 18 can be large, thereby decreasing the constraint ofdesign.

All light striking against the taper-shaped portion 19 b is totallyreflected by the taper-shaped portion 19 b. For example, when thesection of the taper-shaped portion 19 b is designed to be straight asshown in FIG. 7 and θ c is assumed to be a critical angle of the totalreflection, the and gradient β of the taper-shaped portion 19 b isdesigned by the equation below;β≧θ c−θ aTherefore, all light emitted from the light emitter 12 to strike againstthe taper-shaped portion 19 b is totally reflected by the taper-shapedportion 19 b to be directed toward the light reflecting portion 20.

The configuration of the light reflecting portion 20 is designed so thatthe light totally reflected by the flat portion 19 a and thetaper-shaped portion 19 b is reflected by the light reflecting portion20 to be emitted forward from the total reflection region 19.

Therefore, according to this embodiment, the loss of light is reduced,and the design flexibility of the direct emission region 18 is improved.

Fifth Embodiment

FIGS. 8 and 10 show perspective and sectional views of a light emissionsource 24 according to a fifth embodiment of this invention. FIG. 9shows a perspective view showing an inner component of the lightemission source 24 viewed through a mold resin 13. FIG. 11 is anenlarged view of a portion A of FIG. 10. The light emission source 24employs a light reflecting portion 20 which has a parabola-shaped metalmember formed by press working and is plated with aluminum or silver ona surface of the portion for a specular working. If desired, the lightreflecting portion 20 may employ a pressing part with aluminum or silverwhich is chemically processed to bring glossiness on a surface thereof.

The light reflecting portion 20 at a core thereof includes an aperture20 a for accommodating a stem 15. The stem 15 mounted by a light emitter12 is put without any contact with the aperture 20 a, and the lightreflecting portion 20 is sealed within a mold resin 13 together withlead frames 14 and 17.

On a front wall of the mold resin 13, there are formed a direct emissionregion 18 in the center of the resin, a taper-shaped portion 19 b aroundthe region, and a flat portion 19 a around the portion 19 b, in the samemanner as the configuration of the embodiment shown in FIG. 7.

According to this light emission source 24 having such above-mentionedconstruction, any evaporation film (light reflecting portion 20) is notnecessary to be disposed on a rear wall of the mold resin 13 as shown inthe embodiment of FIG. 3, and the light reflecting portion 20 formedtogether with the light emitter 12 and the lead frames 14 and 17 as asingle isolated unit has only to be set within a molding metal mold,thereby simplifying the manufacturing process.

As shown in FIG. 11, an outer circumference portion of a front of themold resin 13 is provided with a taper-shaped beveling portion 25, andan angle of outer circumferential face of the light reflecting portion20 is designed to accord with an angle B of the beveling portion 25.Accordingly, when the mold resin 13 is molded, setting can be done whileangle of the outer circumference at a reflection side of the lightreflecting portion 20 strikes against an inner wall of a cavity of themolding metal mold, the light reflecting portion 20 can be fixed itsposition to be precisely inserted within the mold resin 13, therebyimproving the mounting accuracy of the light reflecting portion 20.

Sixth Embodiment

FIG. 12 is a sectional view of a light emission source 26 according to asixth embodiment of this invention. This light emission source 26 has asimilar construction to that of the fifth embodiment, but a totalreflection region 19 is composed of only a flat portion perpendicular toan optical axis of a light emitter 12.

In addition, at least a region of the light reflecting portion 20stricken by the light reflected by the total reflection region 19 servesas a concave mirror, such as a spherical mirror or a parabolic mirror ofrevolution, having a focal point at a position of a mirror image 12 a ofthe light emitter 12 with respect to the total reflection region 19, assimilarly described in the first embodiment. Accordingly, the lightemitted from the light emitter 12, totally reflected by the totalreflection region 19, and reflected by the light reflecting portion 20passes through the total reflection region 19 to be emitted forward asparalleled light.

Seventh Embodiment

FIG. 13 is a sectional view of a light emission source 27 according to aseventh embodiment of this invention, in which a total reflection region19 has a reverse circular cone-shaped configuration. Since the totalreflection region 19 is formed to have the reverse circular cone-shapedconfiguration so that its outer circumferential portion appears forward,an incident angle of light emitted from the light emitter 12 andstriking against the total reflection region 19 can be designed to belarge, whereby an aperture of an inner circumference portion of thetotal reflection region 19 can be made small. Accordingly, the ratio oflight totally reflected by the total reflection region 19 and reflectedby the light reflection portion 20 to be emitted from the totalreflection region 19 can be large, whereby a light emission sourcehaving an optional directivity can be easily realized by optimallydesigning the configuration of the light reflecting portion 20.

Though not shown, the total reflection region 19 may be modified to havea circular cone-shaped configuration so that its outer peripheral potionappears backward. When the total reflection region 19 has the circularcone-shaped configuration, the light emitted from the total reflectionregion 19 can be gathered inner side, whereby a dark area near thedirect emission region 18 can be minimized.

Eighth Embodiment

FIG. 14 is a sectional view of a light emission source 28 according toan eighth embodiment. In this light emission source 28, a front wall ofa mold resin 13 is formed to have a curved surface on which a directemission region 18 and a total reflection region 19 are smoothly formed,whereby most of light emitted forward from a light emitter 12 is totallyreflected by the front wall of the mold resin 13 (the total reflectionregion 19) and reflected by a light reflecting portion 20 to be emittedforward. According to the light emission source 28 of such aconfiguration, the design flexibility of the light emission source 28 isimproved.

Ninth Embodiment

FIG. 15 is a sectional view of a light emission source 29 according to aninth embodiment. In this embodiment, a total reflection region 19 has acontinuously varying curved face such as lens-curved face, and thedegree of freedom of design is further improved.

Tenth Embodiment

FIG. 16 is a sectional view of a light emission source 30 according to atenth embodiment. In the light emission source 30 of this embodiment, alens configuration of a lens-shaped direct emission region 18 is formedto be a Fresnel lens to decrease the thickness of the direct emissionregion 18 or the light emission source 30.

Eleventh Embodiment

FIG. 17 is a sectional view of a light emission source 31 according toan eleventh embodiment. In the light emission source 31 of thisembodiment, a rear face of a mold resin 13 is formed to include aFresnel lens on a surface of which a light reflecting portion 20 isformed. In this embodiment, the thickness of the light emission source31 can be reduced.

Twelfth Embodiment

FIG. 18 is a sectional view of alight emission source 32 according to atwelfth embodiment. In this embodiment, a mirror 33 is disposed near alight emitter 12 within a mold resin 13 so as to reflect the lightemitted sideway from the light emitter 12 toward a total reflectionregion 19. The light reflected by the mirror is totally reflected by thetotal reflection region 19, and further reflected by a light reflectingmember 20 to be emitted forward from the total reflection region 19. Ifdesired, the mirror 33 may be formed on an inner wall of a stem 15 (seeFIG. 24).

According to this embodiment, the light emitted sideway in the lightemitted from the light emitter 12 is directly reflected by the lightreflecting portion 20 to be avoided from becoming lost light, wherebythe light emitted in a side direction is effectively used and the useefficiency of light emitted from the light emitter 12 is furtherimproved.

Thirteenth Embodiment

FIG. 19 is a sectional view of alight emission source 34 according to athirteenth embodiment. In this embodiment, a light emitter 12 isdisposed in the location deviated from an optical axis D of a moldresin. Since the light emitter 12 is located apart from a directemission region 18 and a total reflection region 19, so that biasedlight is emitted from the light emission source 34 in an inclineddirection. In other words, the directional pattern can be asymmetrywithin a face which light emitter 12 is inclined.

Fourteenth Embodiment

FIG. 20 is a sectional view of a light emission source 35 according to afourteenth embodiment of this invention. The light emission source 35 ofthis embodiment has a similar construction to that of the light emissionsource 26 as shown in FIG. 12, but the position of light emitter 12 isshifted from the center of light reflecting portion 20 and an opticalaxis D of direct emission region 18.

In other words, the light emitter 12 is disposed at a little displacedlocation to a direction perpendicular to the optical axis of the directemission region 18. At least a region of the light reflecting portion 20stricken by the light reflected by total reflection region 19 serves asa concave mirror, such as a spherical mirror or a parabolic mirror ofrevolution, and a center of the light reflecting portion 20 is disposedso as to accord with the optical axis D of the direct emission region18. The concave mirror and the light emitter 12 have a positionalrelationship such that a mirror image 12 a of the light emitter 12 withrespect to the total reflection region 19 is located at a position apartfrom a focal point of the concave mirror in a wall which passes thefocal point of the concave mirror and is perpendicular to the opticalaxis of the concave mirror. In other words, the light emitter 12 isdisposed at the location displaced from a mirror image position of thefocal point of the concave mirror with respect to the total reflectionregion 19.

Therefore, in this light emission source 35, the light emitted from thelight emitter 12 passes the direct emission region 18 to be emitted in adiagonal direction as approximately paralleled light. The light emittedfrom the light emitter 12, totally reflected by total reflection region19 and further reflected by the light reflecting portion 20 is emittedin a diagonal direction as approximately paralleled light.

Fifteenth Embodiment

FIG. 21 is a sectional view of a light emission source 36 according to afifteenth embodiment. In this embodiment, a plurality of light emitters12R and 12G having different light emission colors respectively (forexample, a red light emitting diode, a green light emitting diode) aresealed within the mold resin 13.

When a plurality of light emitters each in a chip shape are enclosedwithin the mold resin in a cannonball-shaped light emission source 37 (acomparative example) as shown in FIG. 22, the color isolation is largeand varies depending on a viewing direction, and visual performancedepends on the viewing direction. In the light emission source 36 ofthis invention, the difference of degrees of color isolation by itsviewing direction can be small, and its visual performance can beuniformed.

Sixteenth Embodiment

FIG. 23 is a sectional view of a light emission source 38 according to asixteenth embodiment. In this embodiment, an optical multilayer film 39is formed over a whole front wall of a mold resin 13. By forming theoptical multilayer film 39 on the front wall of the mold resin 13, thelight having an incident angle larger than a particular angle isreflected by a boundary surface and the light having an incident anglesmaller than the particular angle is driven to pass through. Moreover,the particular angle can be optionally chosen by design of the opticalmultilayer film 39, thereby increasing the degree of freedom of thedesign. The light emission source including the optical multilayer film39 may be any of light emission sources shown in FIGS. 3 to 20 or otherlight emission source, if desired.

Seventeenth Embodiment

FIG. 24 is a sectional view of a light emission source 41 according to aseventeenth embodiment. Before describing the light emission source 41of this embodiment, embodiments for comparison will be describedhereinafter to ease understanding this embodiment.

For instance, in the light emission source as shown in FIG. 10 or 12,the cup in a parabola shape (light reflecting member) is disposed on thestem 15 at a top end of the lead frame 17 so that the light emitter 12mounted within the stem 15 is surrounded by the cup. This is because thelight emitted from a side wall of the light emitter 12 (LED bare chip)is reflected by an inner surface of the cup to be emitted forward. Thuscup within the stem is conventionally employed, but the conventional cupis slanted toward roughly 45 degrees against the optical axis of thelight emitter.

FIG. 27 shows an embodiment in which a conventional cup 40 is employedin the light emission source shown in FIG. 12 as it is. The optical axisof light emitted from direct emission region 18 is fixed by an angleconnecting a light emission point with a principal point of the directemission-region 18. The light emitted by the cup 40 can be regarded asthe light where the cup 40 is a virtual light source. Namely, a mirrorimage of the light emitter 12 with respect to the cup 40 appears in aring shape near an outer circumference of an inner wall of the cup 40.The distance between the light emitter 12 and the cup 40, however, isvery short, so that the mirror image of the light emitter 12 appearsvery near the cup 40, or almost accords with the cup 40. As shown inFIG. 27, the light emitted after reflection by the cup 40 can beregarded as the light emitted from respective points on a surface of thecup 40 (virtual light source), so that an optical axis of the lightwhich is emitted from the light emitter 12, reflected by the cup 40 andemitted from the direct emission region 18 declines, and the light isemitted in a slant direction.

In a conventional light emission source with the use of this cup 40 (forexample, a cannonball shape as shown in FIG. 22), the distance betweenthe light emitter and the lens is long, so that the gradient of theoptical axis of such emitted light is small, so that any substantialproblem has not happened. In the light emission source of thisinvention, the distance between the light emitter 12 and the directemission region 18 is short, so that the gradient of the optical axis ofthe emitted light reflected by the cup 40 becomes large, whereby thelight which is emitted forward from the light emitter and the lightwhich is emitted from a side of the light emitter 12 and reflected bythe cup 40 cannot be emitted in approximately same direction.

As a result, when the light emission source of this invention employs aconventional cup having a gradient roughly 450 the light emitted fromthe light emitter 12 is mixed with the light L1 emitted in approximatelyin the optical axis and the light L2 emitted in a direction greatlydeviated from the optical axis. In particular, as it becomes far fromthe light emission source, the light emitted in different directions issplit so that the light L2 appears in a ring shape around the light L1.Moreover, the direct emission region 18 cannot be designed together withthe front light and the sideway light of the light emitter 12, wherebythe optical lens is designed about the front light, and the optical axisof the slant light L2 cannot be controlled by the design of a lens shapeof the direct emission region 18.

The above-mentioned embodiments are improved by stem 15 in thisseventeenth embodiment. The light emission source 41 of FIG. 24 employsa similar construction to the embodiment shown in FIG. 12, and providesan improvement. FIG. 25 at (a) and (b) shows a front view of a leadframe and a partially sectional side view of the same. In thisembodiment, stem 15 also is disposed for mounting light emitter 12, anda cup 42 for light reflection is disposed around amounting position forthe light emitter on the stem 1. The light emitter 12 is mounted on aninside face of the cup 42 on a front wall of the stem 15. As shown inFIG. 26 which is a partially magnified view of FIG. 24, theconfiguration of the cup 42 is designed so that the light emittedsideway from the light emitter 12 and reflected by the cup 42 can bedirected to the total reflection region 19 without going to the directemission region 18. As concretely shown in FIG. 25, a gradient angle yof the cup 42 from a bottom inner wall of the stem at an inner side ofthe cup 42 is designed to be 22 degrees.

Since the gradient angle y of the cup 42 is small and the lightreflected by the cup 42 is directed to the total reflection region 19 inthis light emission source 41, the light emitted from a side wall of thelight emitter 12 and reflected by the cup 42 is totally reflected by thetotal reflection region 19 to be directed to the light reflectingportion 20, and further reflected by the light reflecting portion 20 topass through the total reflection region 19 for forward emission asshown in FIG. 24. The light striking against the direct emission region18 among the light emitted from a front of the light emitter 12 becomessubject to a lens function on the direct emission region 18, and isemitted forward.

Thus, the light reflected by the cup 42 is totally reflected by thetotal reflection region 19 to be directed to the light reflectingportion 20, whereby the light path can be freely controlled by the lightreflecting portion 20. Accordingly, when the light reflected by the cup42 employing lead frames 14 and 17 is directed to the total reflectionregion 19, almost all light emitted from the light emitter 12 can beemitted to a desired direction (for example, a direction in parallelwith the optical axis of the light emitter 12). In this embodiment, thelight emission source 41 is free from becoming large.

The reason why the light path can be freely controlled by directing thelight reflected by the cup 42 toward the total reflection region 19 willbe explained hereinafter. Before the light emitted from a front and aside of the light emitter 12 reaches the light reflecting portion 20,the light path is bent by the reflection at the total reflection region19, so that the light path length from the light emitter 12 to the lightreflecting portion 20 becomes long, whereby the light reflecting portion20 receives the light emitted from a front of the light emitter 12 andthe light emitted from a side of the light emitter 12 and reflected bythe cup 42 in approximately same directions respectively. Accordingly,they can be simultaneously controlled. When the curvature of the lightreflecting portion 20 is designed, both are possible to be generallydesigned.

Eighteenth Embodiment

FIG. 29 is a sectional view of a light emission source 43 according toan eighteenth embodiment. This embodiment is of a can package type, inwhich a front wall of a light reflecting portion 20 is filled with atransparent mold resin 13, a rear wall of the light reflecting portion20 is filled with an insulating material 46, a cylindrical housing 44extending from outer circumferential portion of the light reflectingportion 20 covers an outer peripheral surface of the insulating material46, and a flange 45 is disposed at a periphery of a rear end of thehousing 44.

In addition, the light reflecting portion 20 in the center thereof isformed with the stem 15 as a single unit. Further, light reflectingportion 20, stem 15, lead frame 17, cylindrical housing 44 and flange 45are formed as a single unit by metallic material. A head of the leadframe 14 is inserted within an aperture 20 a of the light reflectingportion 20 without contact with the same.

Therefore, according to this embodiment, the number of parts is reduced,the assembly is easy, and manufacturing cost is reduced. In particular,it gets possible to produce it by a production process same as generalcan package products. Furthermore, the housing 44 and the flange 45united with the stem 15 are exposed to a surface, whereby heatdissipation nature of the heat which is occurred with the light emitter12 is improved, and the allowance forward current quantity is increased,thereby performing high brightness.

Furthermore, in this embodiment, the cup 42 disposed on the stem 15 isdesigned so that the light emitted from a side of the light emitter 12and reflected by the cup 42 can be directed toward the total reflectionregion 19, whereby each emission direction of the light emitted from thelight emission source 43 can be aligned in one direction.

Several embodiments for a light receiver will be described hereinafter.

Nineteenth Embodiment

FIG. 30 is a perspective view of a light receiver 51 according to anineteenth embodiment of this invention, and FIG. 31 is a sectional viewof the receiver. According to this light receiver 51, a photo detector52 in a chip shape, such as a photo diode or photo-transistor or thelike, and a light reflecting portion. 53 are sealed within a mold resin54 made of a transparent resin material. The photo detector 52 sealedwithin the mold resin 54 is mounted on a stem 56 disposed on a head of alead frame 5, connected with another lead frame 58 by a bonding wire 57,and disposed so that its light receiving wall faces forward.

In a front central part of the mold resin 54, there is provided a directincidence region 59 having a convex lens configuration such as aspherical lens shape, an aspherical lens shape, or a paraboloid shape. Aflat region 60 (resin boundary surface) having flatness is formed tosurround the direct incidence region 59. The direct incidence region 59is formed so that its medial axis may accord with an optical axis of thephoto detector 52. The flat region 60 has a flat face perpendicular tothe optical axis of the photo detector 52. The photo detector 52 islocated at a focal point of the direct incidence region 59 or itsneighborhood, and the light striking against the direct incidence region59 in the light approximately perpendicularly striking against the photodetector is focused to the photo detector 52 to be received by its lightreceiving face.

An angle α of a direction, viewed from the photo detector 52 toward aboundary between the direct incidence region 59 and the flat region 60,from the optical axis is equal to a critical angle θ c of the totalreflection between the mold resin 54 and air or larger.

A light reflection portion 53 is a metal plate which is molded to aparabola shape by press working and plated with aluminum or silver onits surface for specular working. If desired, the light reflectionportion 53 may employ a pressed part of aluminum or silver which isapplied by chemical treatment for providing glossiness on its surface.The light reflecting portion 53 at its center is provided an aperture 61for accommodating a stem 56, and is sealed within a mold resin 54together with lead frames 55 and 58 wherein the stem 56 mounted by thephoto detector 52 is accommodated within the aperture 61. Aconfiguration of a section of the light reflecting portion 53 isdesigned so that the light perpendicularly striking against the flatregion 60 of the mold resin 54 and reflected by the light reflectingportion 53 may be totally reflected by the flat region 60 to enter intothe photo detector 52.

Accordingly, the light striking against the direct incidence region 59in the light approximately perpendicularly striking against the lightreceiver 51 is refracted to be focused on the photo detector 52 when itpasses the direct incidence region 59. The light striking against theflat region 60 is reflected by the light reflecting portion 53, andtotally reflected by the flat region 60 to be focused on the photodetector 52. Thus, most of light approximately perpendicularly strikingagainst the light receiver 51 can be focused on the photo detector 52,whereby the light receiver 51 having a high efficiency of light receiptcan be produced. The light requirement can be increased by increasingthe light receive area which can be performed by enlarging the lightreflecting portion 53 without depending on the area of the photodetector 52, thereby increasing the light requirement and the lightreceiving efficiency at a reduced cost. Moreover, thinning the lightreceiver 51 can be performed by increasing the light receivingefficiency without thickening the receiver.

According to the light receiver 51 having such a configuration, thelight reflecting portion 53 which is a discrete part together with thephoto detector 52 and the stem 56 has only to be set within a moldingmetal mold, thereby simplifying the manufacturing process of the lightreceiver 51.

The angle of a circumference face of the light reflecting portion 53 isadjusted to the angle portion of the mold resin 54. Accordingly, whenthe mold resin 54 is molded, an outer circumferential angle on areflection side of the light reflecting portion 53 coming into contactwith an inner wall of a cavity of molding metal mold can be set, wherebythe light reflecting portion 53 is fixed about its position to beprecisely inserted within the mold resin 54, thereby improving themounting accuracy of the light reflecting portion 53.

Twentieth Embodiment

FIG. 32 is a sectional view of a light receiver 62 according to atwentieth embodiment. In this embodiment, a direct incidence region 59is disposed at a center of a surface core of the mold resin 54, ataper-shaped portion 63 in a circular cone (block) or pyramid (block)shape which hollows at its center is disposed around the directincidence region 59, and a flat region 60 is disposed outside theportion 63. The medial axis of the taper-shaped part 63 agrees with anoptical axis of a photo detector 52, and the flat region 60 has a faceperpendicular to a photo detector 52.

According to this light receiver 62, the incident light to the directincidence region 59 is refracted to be directed to the photo detector52. The light almost perpendicularly striking the flat region 60 isreflected light reflecting portion 53, and further totally reflected bythe flat region 60 to be directed to the photo detector 52. Thetaper-shaped portion 63 is designed so that the light entering throughthe flat region 60 to be reflected by an outer circumferential portionof the light reflecting portion 53 can be directed to the photo detector52 without totally reflected in a direction deviating from the photodetector 52 when it is totally reflected near the direct incidenceregion 59. According to this embodiment, the light receiving efficiencyis improved. The employment of the taper-shaped part 63 allows theprojection length of the direct incidence region 59 to be decreased andthe light receiver 62 to be thinned.

According to thus construction, an angle a of a direction, viewed fromthe photo detector 52 toward a boundary between the direct incidenceregion 59 and of the taper-shaped part 63, from the optical axis can besmaller than a critical angle θ c of the total reflection between themold resin 54 and air.

Twenty-First Embodiment

FIG. 33 is a perspective view of a light receiver 64 according to atwenty-first embodiment, which is used as a solar cell. In this lightreceiver 64 (solar cell), a light reflecting portion 53 a longitudinallyuniform section of which has a parabola-shape is sealed within moldresin 54. In front of the light reflecting portion 53, there is disposeda photo detector 52 (a photoelectric transducer such as a silicon systemphotoelectric transducer of amorphous, polycrystal or monocrystal). Inthe center of a front wall of the mold resin 54 there is disposed adirect incidence region 59 in a longitudinally cylindrical lens-shape,and a flat region 60 is formed at each side thereof.

The light striking against the direct incidence region 59 in the lightperpendicularly striking against the light receiver 64 is directlyfocused on the photo detector 52. The light striking against the flatregion 60 is reflected by the light reflecting portion 53, and furthertotally reflected by the flat region 60 to be received by the photodetector 52. Since the photo detector 52 is long in one direction, thelight receiving area can be increased, thereby performing large focusedquantity and providing a high generating capacity as a solar cell.

Generally, the energy conversion efficiency of a conventional solar cellis only 15%. Accordingly, in order to increase the generating capacity,the area of the photoelectric transducer itself has to be increased withincreasing manufacturing cost. According to the light receiver 64 (solarcell) of this invention, however, the light receiving area can beincreased so as to efficiently focus the light striking against thelight receiving area to the photo detector 52 by increasing the wholearea of the light receiver 64 without increasing the area of thephotoelectric transducer itself, thereby enhancing the generatingcapacity with an economy means. In particular, according to theconfiguration of this embodiment, the light focus efficiency can beincreased two times or more, and the substantial energy conversionefficiency also can be increased two times or more.

Furthermore, according to this light receiver 64, the efficiency can beenhanced with retaining the thin configuration, whereby a thinconfiguration can be applied to a solar panel put on a roof of a house,a road tack, or delineator.

In the light receiver 64 shown in FIG. 30 or 31, a photoelectrictransducer can be mounted as the photo detector 52.

Twenty-Second Embodiment

FIG. 34 is a perspective view of a light emission source 65 according toa twenty-second embodiment, FIG. 35 at (a) is a front view of thesource, FIG. 35 at (b) is a sectional view taken along line X1-X1 ofFIG. 35 at (a), and FIG. 35 at (c) is a sectional view taken along lineY1-Y1 of FIG. 35 at (a). In this embodiment, a light emitter 12 such asa light emitting diode (LED chip) is sealed in a mold resin 13 made of atransparent resin material. The light emitter 12 sealed in the moldresin 13 is mounted on a stem 15 disposed on a leading edge of a leadframe 17, and connected with another lead frame 14 by means of a bondingwire 16, and a light emission side thereof is disposed toward a front ofthe light emission source 65.

A light reflecting portion 20 is composed of a metallic component whichis molded in a parabola shape by press working, and its surface isapplied by specular working of plating aluminum or silver thereon. Ifdesired, the light reflecting portion 20 may be done by chemicalprocessing applied to a pressed part made of aluminum or silver to bringglossiness on the surface thereof. The light reflecting portion 20 at acenter thereof includes an aperture 20 a for accommodating the stem 15,and is sealed with the lead frames 14 and 17 within the mold resin 13where the aperture 20 a accommodates the stem mounted by the lightemitter 12.

As shown in FIG. 35 at (a), the light reflecting portion 20 has majorand minor axis directions when it is viewed from its front, and agenerally elliptic shape in this embodiment. An outer circumferentialedge of the light reflecting portion 20 is formed to be in parallel witha front face of the mold resin 13, whereby any large clearance does notoccur between the outer circumferential edge of the light reflectingportion 20 and the front face of the mold resin 13 so that any light isprevented from leaking through the clearance and becoming loss.

The section in the major axis direction as shown in FIG. 35 at (b) andthe section in the minor axis direction as shown in FIG. 35 at (c) arecurved in a concave, but in different shapes. In other words, thedistribution field of curvature of the section in the major axisdirection is different from the distribution field of the section in theminor axis direction. The distribution field of curvature of the sectionin the major axis direction is shifted toward a smaller value than thedistribution field of the section in the minor axis direction.

As long as the section of the light reflecting portion 20 is in an arcshape either in the major and minor axis directions, when a radius of asection in the major axis direction is R1 and a radius of the section inthe minor axis direction is Rs;(1/R1)<(1/Rs)In other words, the radius R1 in the major axis direction is larger thanthe radius Rs in the minor axis direction(R1>Rs).

When the section of the light reflecting portion 20 is not arc-shaped,the curvature varies with a location in the sections of the major andminor directions so that it has a spread (distribution). For instance,this case can be featured by a central value of a distribution ofcurvature. Assuming that the curvature in the major direction has theminimum value (ρl)min and the maximum value (ρ l)max and the curvaturein the minor direction has the minimum value (ρ s)min and the maximumvalue (ρ s)max, the respective central values (ρ l)c and (ρ s) areexpressed by the following equations;Major axis direction: (ρ l)c={(ρ l)min+(ρ l)max}/2Minor axis direction: (ρ s)c={(ρ s)min+(ρ]s)max}/2Accordingly, in the light reflecting member 20 employed in the lightemission source 65 according to this invention, the central value (ρ l)cof the curvature in the section in the major axis direction has only tobe smaller than the central value (ρ s) of the curvature in the sectionin the minor axis direction as expressed by the following equation;(ρ l)c<(ρ s)c

If desired, both ends of the distribution of curvatures are featured bythe minimum and maximum values, and the following equation may be made;(ρ l)min≦(ρ s)min(ρ l)max≦(ρ s)maxprovided that this equal sign does not happen simultaneously.

In a front central portion of the mold resin 13, there are formed adirect emission region 18 in a convex lens shape, and a total reflectionregion 19 of a flat shape to surround the direct emission region 18. Thedirect emission region 18 is formed so that its optical axis accordswith the optical axis of the light emitter 12, and the total reflectionregion 19 is a plane perpendicular to the optical axis of the lightemitter 12. The light emitter 12 is located in a focal point of thedirect emission region 18 or in its neighborhood. The angle of adirection against the optical axis, viewed from the light emitter 12toward a boundary between the direct emission region 18 and the totalreflection region 19, is designed to be equal to the critical angle θ cof the total reflection between the mold resin 13 and air, or larger.

When the direct emission region 18 having a lens shape is viewed fromits front, it has a generally ellipse shape having a major axisdirection and a minor axis direction, and the respective major and minoraxis directions accord with the major and minor axis directions of thelight reflecting portion 20. In the direct emission region 18, thedistribution field of curvature of a section in a major axis directionis different from the distribution field of curvature of a section in aminor axis direction, and, particularly, the curvature distribution ofthe section in the major axis direction is shifted to a side of asmaller value than the curvature distribution of the section in theminor direction. Shifting the curvature distribution of the section inthe major axis direction to the side of the smaller value than thecurvature distribution of the section in the minor direction has samemeaning as that of the light reflecting portion 20.

The light radiated to the direct emission region 18 in the light emittedfrom the light emitter 12 is directly emitted forward from a front ofthe mold resin 13 as an approximately paralleled light. The lightemitted to the total reflection region 19 in the light emitted from thelight emitter 12 is totally reflected by a resin boundary surface, andalmost of the totally reflected light by the resin boundary surface isreflected by the light reflecting portion 20 to be emitted forward fromthe total reflection region 19. Thus, almost all light emitted forwardlyfrom the light emitter 12 (viz. including the light totally reflected bythe total reflection region 19) can be brought into a front of the lightemission source 65, thereby improving the efficiency of light use.Moreover, the light emitted forward from the light emitter 12 is emittedfrom the direct emission region 18 without any obstruction, wherebydarkness on the optical axis as found in the above-describedconventional light emission source is avoided and the directive patternis improved.

Furthermore, the light emitted from the light emitter 12 in a diagonaldirection is totally reflected by the total reflection region 19, andreflected by the light reflecting portion 20 to be emitted forward so asto prolong the light length becomes long, whereby the aberration isreduced and the light emission source 65 can be provided with a highaccuracy.

The light reflecting portion 20 has a generally ellipse configuration,whereby the light reflected by the light reflecting portion 20 to beemitted forward becomes beams having an emission profile in a generallyelliptic shape as shown in FIG. 36. The direct emission region 18 alsohas a generally elliptic shape a major axis direction of which accordswith the major axis direction of the light reflecting portion 20, sothat the light beams emitted from the direct emission region 18 have asection in a generally elliptic shape. Accordingly, as shown in FIG. 37,the light emitted from the direct emission region 18 supplements thelight emitted from the total reflection region 19, so that combinationof the light emitted from the direct emission region 18 and the lightemitted from the total reflection region 19 provides emission lighthaving an approximately uniform intensity elliptic profile.

When, in order to emit light in a generally elliptic shape spreading inone direction, a hemisphere-shaped metal member having a constantcurvature in an optional direction is prepared and both sides of themetal member are cut to provide a light reflecting portion which islengthened longitudinally, there appears a large clearance between thecut portion and a front face of the mold resin through which lightleaks, thereby deteriorating the efficiency of light use. Such aclearance can be reduced by having a curvature varying with directions,thereby enhancing brightness of the light emission source 65. When thecurvatures in orthogonal two directions in the light reflecting portion20 having a circle in its front view are different, the spread of thereflection light can be different, thereby providing emission light of agenerally elliptic profile spreading in one direction. When the lightreflecting portion 20 has an elliptic shape, the design of the lightreflecting portion 20 becomes easy.

The light reflecting portion 20 can be realized by employing anaspherical surface of a toric surface or a biconical surface, and a moreuniform beam profile can be designed. FIG. 38 at (a) shows a lightreflecting portion 20 formed with a biconical surface. When the lightreflecting portion 20 has an X axis in a major axis direction, a Y axisin a minor axis direction, and a Z axis in a front direction, the lightreflecting surface of the light reflection portion 20 having thebiconical surface can be expressed by the following equation (1);$\begin{matrix}\left\lbrack {{Equation}\quad 1} \right\rbrack & \quad \\{Z = \frac{\left( {{cvxX}^{2} + {cvY}^{2}} \right)}{1 + \quad\sqrt{\begin{matrix}{1 - {{{cvx}^{2}\left( {{ccx} + 1} \right)}X^{2}} - {{{cv}^{2}\left( {{cc} + 1} \right)}Y^{2}} +} \\{{aX}^{4} + {bY}^{4} + {cX}^{6} + d^{6} + \ldots}\end{matrix}}}} & (1)\end{matrix}$

When a sectional configuration in a XZ plane of the biconical surface isexpressed by “Z=g1(X)”, a curvature of the curve is expressed by “cv”,the conic coefficient is expressed by “cc”, and a sectionalconfiguration in a YZ plane is expressed by “Z=g2(Y)”, the curvature ofthis curve becomes “cvx(≠cv)”, and the conic coefficient becomes “ccx”,provided that “a,b,c,d” are coefficients of terms of high order.

Twenty-Third Embodiment

FIG. 39 at (a) is a front view of a light emission source 66 accordingto a twenty-third embodiment. FIG. 39 at (b) and (c) shows sectionalviews taken along lines X2-X2 and Y2-Y2 of FIG. 39 at (a). A front of alight reflecting portion 20 is of a rectangular, and formed to be curvedin a convex shape on sections in its major and minor axis directions.The light reflecting portion is sealed within a mold resin 13 molded ina rectangular shape, and an external of the light emission source 66 hasa rectangular configuration when it is viewed from its front.

The light emission source 66 having such a configuration can emit lightbeams that are uniform in a generally elliptic-shaped profile as shownin FIG. 40, same as the fifteenth embodiment.

Twenty-Fourth Embodiment

FIG. 41 at (a) is a front view of a light emission source 67 accordingto a twenty-fourth embodiment. FIG. 41 at (b) and (c) shows sectionalviews taken along lines X3-X3 and Y3-Y3 of FIG. 41 at (a). In thisembodiment, there is employed a light reflecting portion 20 having afront configuration in a generally rectangular shape which is made bycutting four sides of a light reflecting portion 68 having a frontconfiguration in an elliptic shape as shown in two-dotted lines of FIG.41. This is sealed within a mold resin 13 molded in a rectangular shape,and the external configuration of the light emission source 67 has arectangular shape when it is viewed from its front.

Thus constructed light emission source 67 can emit light beams having aprofile in a rectangular shape as shown in FIG. 42. This source 67 isalso preferable to the application of a high mount strap lamp mounted onan automobile because uniform beams are desired to be radiated to alimited rectangular area.

Though the design of a beam profile (directional pattern) in aconventional light emission source (LED) depends on only the parametersof a curvature of an optical lens surface and a spacing between an LEDchip and the lens surface causing the light emission source to becomethick in a direction of an optical axis, the light emission source ofthis invention allows flexible design depending on a configuration ofthe light reflecting portion so that the light emission source 67 maybecome thin in a direction of an optical axis. In other words, the lightemission sources of the twenty-second to twenty-fourth embodiments(FIGS. 34 to 42) may provide thin light emission sources capable ofemitting light to a broad area. Particularly the light emission source67 is desirable in the application, such as a high mount strap lamp,requiring an optically limited narrow space (particularly depth) andradiation to a wide area.

Twenty-Fifth Embodiment

FIG. 43 at (a) is a front view of a light emission source 69 accordingto a twenty-fifth embodiment. FIG. 43 at (b) and (c) shows sectionalviews taken along lines X3-X3 and Y3-Y3 of FIG. 43 at (a). The lightemission source 69 of FIG. 43 includes a tapered portion 19 b of atapered configuration around a direct emission region 18 and a flatportion 19 a around the tapered portion 19 b. The tapered portion 19 bmakes an angle smaller than 90 degrees from a light emission dire, andthe flat portion 19 a is perpendicular to the optical axis. All lightstriking against the flat portion 19 a is totally reflected by settingthe angle of the direction from the light emitter 12, viewed from thelight emitter 12 to a boundary between the tapered portion 19 b and theflat portion 19 a, to become bigger than the critical angle θ c of thetotal reflection on a boundary surface of the mold resin 13. All lightstriking against the tapered portion 19 b is totally reflected bysetting the gradient angle so that the light striking against theboundary between the tapered portion 19 b and the flat portion 19 a canbe totally reflected by the tapered portion 19 b. Accordingly, thetapered portion 19 b and the flat portion 19 a provide a totalreflection region 19, and the light which cannot be totally reflected onthe flat portion 19 a can be totally reflected on the tapered portion 19b, which are directed forward by reflection on light reflecting portion20, thereby improving the efficiency of light emission by the lightemission source 69.

When the light reflecting portion 20 having a generally elliptic shapein a front view is designed, particularly when the light emissionprofile and efficiency in a major direction of the elliptic shape isconsidered, the region (total reflection region 19) where the lightemitted from the light emitter 12 is totally reflected on the boundarysurface of the mold resin 13 becomes narrow or disappears in the minordirection.

In such a case, formation of the tapered portion 19 b becomes effective.In order to increase the total reflection region shown in FIG. 43, thetapered portion 19 b has only to be formed so that the ratio shared bythe tapered portion 19 b in the minor axis direction is larger than theratio shared by the tapered portion 19 a in the major axis direction andthe external configuration of the tapered portion 19 b does not have anysimilarity relationship with the external configuration of the directemission region 18 nor the light reflecting portion 20 when the lightemission source 69 is viewed from its front. There is a case such thatthe major and minor axis directions in the external shape of the taperedportion 19 b when it is viewed from its front are reversed to the directemission region 18 and the light reflecting portion 20. Thusconstruction can improve the efficiency of the light emission source 69in its minor axis direction.

In addition, there is a case with the requirement which brings the lightemitter 12 close to the resin boundary surface like a light emissionsource 70 shown in FIG. 44 when the light emission profile or theefficiency in the minor axis direction is considered in designing orwhen limitation is produced from the external configuration or the lightemission profile of the light emission source 69. In such a case, theremay happen a case such that an emission angle of light emitted from thelight emitter 12 (angle from the optical axis) becomes large, forexample, larger than 70 degrees at an edge of the resin boundary surfacein the major axis direction as shown in FIG. 45 at (a). Thus light ofthe angle has low intensity, so that the light intensity of LED becomessmall and the brightness of the light emission source becomes uneven.

In such a case, the brightness at the edge of the resin boundary surfacecan be improved and the brightness of the light emission source 69 canbecome generally uniform by setting the angle of the tapered portion 19b in a section of the major axis direction into the total reflectionangle or larger so as to bring the light totally reflected at thetapered portion 19 b into the edge of the resin boundary surface asshown in FIG. 45 at (b). In this case, the external configuration of thetapered portion 19 b when the light emission source 69 is viewed fromits front does not always have a similarity relationship with theexternal configuration of the direct emission region 18 or the lightreflecting portion 20, and there may be a case such that the ratio ofthe major axis and minor axis becomes larger.

The configuration having major and minor axis directions when it isviewed from its front can be applied to a light receiver as shown inFIG. 34 and its subsequent figures.

Twenty-Sixth Embodiment

FIG. 46 at (a) and (b) shows front and sectional views of a lightemission source 71 according to a twenty-sixth embodiment. The lightemission source 71 includes a chip-type light emitter 12 such as an LEDchip mounted on a circuit board 73, and a disc-shaped optical module(optical component) 72 disposed to cover the emitter.

The optical module 72 is a mold in which a light reflecting portion 20is insert-molded within a mold resin 13, and a convex lens-shaped directemission region 18 and a total reflection region 19 are formed on asurface of the mold resin 13. In addition, an element mounting portion74 in a concave shape is formed at a position on a rear face of the moldresin 13 corresponding to an aperture 20 a of the light reflectingportion 20 to be accommodated within the aperture 20 a. The elementmounting portion 74 is formed in a generally hemispherical shape to begenerally perpendicular to light in each direction so that an opticalaxis of light emitted from the light emitter 12 is not bent when theemitted light strikes against the optical module 72. The light emissionsource 71 is constructed so that the optical module 72 is put on thechip-type light emitter 12 of a surface-mount type which is mounted onthe circuit board 73 so that the light emitter 12 may be housed withinthe element mounting portion 74. Positional adjustment of the lightemitter 12 and the optical module 72 is eased and it can be efficientlyassembled by matching the dimensions of the element mounting portion 74with the external dimensions of the light emitter 12.

Employment of the optical module 72 can provide same functions andeffects as those in the above-described light emission sources where thelight emitter 12 is buried within the mold resin 13. As shown in FIG. 46at (b), the light emitted forward from the light emitter 12 enterswithin the mold resin 13 through the element mounting portion 74 toadvance within the mold resin 13 for forward emission from the directemission region 18. The light emitted in a diagonal direction from thelight emitter 12 intrudes into the mold resin 13 through the elementmounting portion 74 to advance within the mold resin 13, reaches thetotal reflection region 19 to be totally reflected thereby, and isfurther reflected by the light reflecting portion 20 to be emittedforward through the total reflection region 19. Accordingly, the lightfrom the light emitter 12 is widened to be emitted from the opticalmodule 72 to a large area in comparison with the dimensions of the lightemitter 12, thereby performing a large scale light emission face.

The optical loss by covering with the optical module 72 consists of theincidence loss into the optical module 72, the fresnel loss on emissionfrom a front surface of the mold resin 13, and the minor reflection lossby the light reflecting portion 20, whereby approximately 90% of thelight emitted from the light emitter 12 is efficiently emitted forwardfrom the optical module 72.

Furthermore, the emission direction from the light emission source 71employing the optical module 72 can be freely designed, so thatspatially small construction can be performed in comparison withemployment of an optical lens to obtain same effects. Though most ofapplications employing LED chips have spatial limitations, theemployment of the optical module 72 is effective on the applications.

Thus optical module 72 can be applied to the light emitter 12 alreadymounted on the circuit board 73, so that larger scale and higherefficiency of the light emission area of the light emitter 12 can beperformed in a later manufacturing process.

Though this embodiment employs the LED chip, same effects can beprovided when the optical module 72 is enlarged in dimensions or appliedto a light source such as an electric lamp or a fluorescent lamp otherthan the LED chip.

Twenty-Seventh Embodiment

FIG. 47 is a front view of a light emission source 75 according to atwenty-seventh embodiment. The light emission source 75 includes majorand minor axis directions, and exemplarily employs an optical module 72having a rectangular configuration. As the optical module 72 isemployed, the light spread in the major axis direction is different fromthe same in the minor axis direction, so that emission light having aprofile in a rectangular or elliptic shape can be performed, therebyproviding light emission source 75 corresponding to the twenty-secondembodiment (FIG. 34) by employing the optical module 72.

In addition to this, same functions as those of above-described kinds oflight emission sources can be performed by changing the construction ofthe optical module 72.

Twenty-Eighth Embodiment

FIG. 48 shows a perspective view of a light receiver 76 according to atwenty-eighth embodiment, and FIG. 49 shows a sectional view of thesame. The light receiver 76 is constructed by covering a photo detector52 mounted on a circuit board 73 with an optical module 77, anddisposing the photo detector 52 within an element mounting portion 78.The kind of the photo detector 52 is not particularly limited, but canbe applied to a general photodiode or phototransistor such as a lightreceiver having a lead 50 a as shown in FIG. 50 at (a) and (b).

This optical module 77 is a mold in which a light reflecting portion 53is insert-molded within a mold resin 54, and a direct incidence region59 in a convex lens-shape and a flat region 60 are formed on a surfaceof the mold resin 54. In addition, an element mounting portion 78 in aconcave shape is formed at a position on a rear face of the mold resin54 corresponding to an aperture 61 of the light reflecting portion 53 tobe accommodated within the aperture 61. The element mounting portion 78is formed in a generally hemispherical shape to be generallyperpendicular to light in each direction so that an optical axis oflight emitted from the optical module 77 to the photo detector 52 is notbent. The light receiver 76 is constructed so that the optical module 77may cover the photo detector 52 mounted on the circuit board 73 and thephoto detector 52 may be housed within the element mounting portion 78.Positional adjustment of the photo detector 52 and the optical module 77is eased and it can be efficiently assembled by matching the dimensionsof the element mounting portion 78 with the external dimensions of thephoto detector 52.

In the light receiver 76, the incident light striking against the directincidence region 59 of the optical module 77 advances within the moldresin 54, and exists from the element mounting portion 78 to strikeagainst the photo detector 52. The light striking against the flatportion of the optical module 77 advances within the mold resin 54 to bereflected by the light reflecting portion 53 toward the flat region 60,and the reflected light is further totally reflected by the flat region60 to exit from the element mounting portion 78 for incidence to thephotodetector 52. Accordingly, the optical module 77 serves as a largearea optical lens, and light having a large area can be received by thephoto detector 52 by employing the module 77 which is large incomparison with the photo detector 52.

Though spatially large area is necessary for obtaining similar functionsand effects by employing a lens, a thin configuration can be performedby employing this optical module 77.

In case of light receiver, same function as that of the above-describedvarious kinds of light receivers can be performed by changing theconstruction of the optical module 77.

Thought the optical module 72 for the light emission source and theoptical module 77 for the light receiver are separately described here,but they may be used in common if desired.

Twenty-Ninth Embodiment

FIG. 51 shows a sectional view of a light emission source 79 accordingto a twenty-ninth embodiment. In this embodiment, a light reflectingportion 20 is not inserted within an optical module 72 covering a lightemitter 12. A Fresnel lens-shaped pattern 80 of a reflection type isformed on a rear surface of a mold resin 13 instead, and a reflectioncoating 81 consisting of a metal evaporation film is formed on a surfaceof the pattern 80. In addition, a support portion 82 of a cylindricaltype is molded together with an outer circumferential portion of themold resin 13 as a single unit for stabilization with a surface of acircuit board 73.

By such a configuration, same effect as that of the twenty-seventhembodiment (FIG. 46) is provided. Besides, because insert-molding thelight reflecting portion 20 within the mold resin 13 is not necessary,the number of components can be reduced and the manufacturing cost alsocan be reduced. When the optical module 72 is molded, positioning thelight reflecting portion 20 is not necessary, thereby improvingefficiency of a molding process for the optical module 72.

Thirtieth Embodiment

FIG. 52 shows a sectional view of a light emission source 83 accordingto a thirtieth embodiment. In this embodiment, a direct emission region18 is inconsiderably formed in the center of a surface of a mold resin13, a major portion serves as total reflection region 19. The directemission region 18 is composed of a shallow recess.

In this embodiment, the light emitted forward from the light emitter 12is totally reflected by the total reflection region 19 as far aspossible, and the emission direction can be controlled by the lightreflecting portion 20. This embodiment can respond when any directemission region 18 having a convex lens shape cannot be formed due to aspatial constraint by lifting controllability of outgoing beams, whenthe light emitted from the light emitter 12 has an unbalanced angle ofbeam spread and is not near lambert distribution, when light cannot beemitted in a desired direction in the convex lens-shaped direct emissionregion 18, and when a greater area is necessary and light is wanted tobe distributed to an end surface direction of the optical module 72.

Thirty-First Embodiment

FIG. 53 shows a sectional view of a light emission source 84 accordingto a thirty-first embodiment, in which a direct emission region 18 and atotal reflection region 19 are formed in a planar fashion. As shown inFIG. 54, an element mounting portion 74 of an optical module 72 consistsof a sphere-shaped division 74 a and a small crater 74 c having a narrowwidth which appears from a center of the division 74 a to its frontwithin a mold resin 13. A boundary portion 74 b between thesphere-shaped division 74 a and the crater 74 c curves smoothly. Thesphere-shaped division 74 a and the crater 74 c are formed to beapproximately perpendicular to a direction of the light emitted from thelight emitter 12, and boundary portion 74 b slants against direction ofthe light emitted from the light emitter 12.

In the crater 74 c the light emitted forward from the light emitter 12advances forwardly to be emitted without changing the optical axisdirection. Thus, when the light emission source 84 is viewed from itsfront, light is emitted from its center. In the boundary portion 74 b,the light emitted forward from the light emitter 12 is refracted to bebent to the total reflection region 19, and its emission direction iscontrolled by the light reflecting portion 20. The light emitted fromthe light emitter 12 in a diagonal direction advances at thesphere-shaped division 74 a toward the total reflection region 19without almost changing its optical axis, and is reflected by the lightreflecting portion 20 to control its emission direction. According tothus construction, the light emitted forward from the light emitter 12is totally reflected by the total reflection region 19 as far aspossible, and the emission direction of the light can be controlled bythe light reflecting portion 20 in the same manner as that of thethirtieth embodiment (FIG. 52). Moreover, the crater 74 c prevents acenter of the light emission source 84 from becoming dark when it isviewed from its front.

Thirty-Second Embodiment

FIG. 55 shows a sectional view of a light emission source 85 accordingto a thirty-second embodiment, in which a direct emission region 18 anda total reflection region 19 are formed in a planar fashion. An elementmounting portion 74 of an optical module 72 is formed in a truncatedcone configuration.

The optical module 72 employing the element mounting portion 74 havingsuch a configuration can emit the light emitted from the light emitter12 to a top face of the element mounting part 74 toward its frontwithout changing its direction. As shown in FIG. 56, in the lightemitted from the light emitter 12 to an incline surface of the elementmounting portion 74, light L4 near the top face is refracted to thetotal reflection region 19 (this light L4 goes straight as shown bybroken lines in the event of a sphere-shaped element mounting portion74), and its emission direction is controlled by light reflectingportion 20. Light L5 perpendicularly striking against the inclinesurface of the element mounting portion 74 from the light emitter 12goes straight to be totally reflected by the total reflection region 19,and its emission direction is controlled by the light reflecting portion20. Accordingly, this embodiment can provide same effect as that of thethirty first embodiment.

Furthermore, when the element mounting part 74 is sphere-shaped, lightL6 emitted from light emitter 12 to a side direction (at an angle ofabout 70 degrees or greater to the optical axis) directly strikesagainst the light reflecting portion 20 to be reflected thereby forspreading outwardly as shown in broken lines. When the element mountingpart 74 is in a truncated cone shape, the light L6 is refracted with theincline of the element mounting portion 74 to go straight to the totalreflection region 19 for total reflection, and the totally reflectedlight is reflected by the light reflecting portion 20 to be emittedforward.

Thirty-Third Embodiment

FIG. 57 at (a) shows a sectional view of a light emission source 311 inwhich a light emitter 313 is engaged with an optical module 312according to a thirty-third embodiment of this invention. In the lightemitter 313, an LED chip 316 is mounted on a stem 315 disposed on a headof a lead 314, and the LED chip 316 and another lead 317 are connectedby a bonding wire 318, which are molded with a transparent mold resin319 in a cannonball shape. The light emitter 313 is a conventionalcomponent which is commercially available.

As shown in FIG. 57 at (b), in the optical module 312, a lightreflecting member 321 insert-molded within a transparent resin 320. Theoptical module 312 has a circle cyclic or doughnut shaped configuration,an open hole (aperture) 322 in the center of the module serves as anelement mounting position for mounting the light emitter 313. The lightreflecting member 321 is a metal component molded in a parabola shape bypress working, a center of which is open in accordance with the openhole of the optical module 312, and a surface of which is processed withspecular working by aluminum or silver plating. If desired, the lightreflecting portion 321 may be done by chemical processing applied to apressed part made of aluminium or silver to bring glossiness on thesurface thereof. An outer circumferential edge or inner circumferentialedge of the light reflecting member 321 is designed to be positioned ata corner of an outer circumferential side or inner circumferential sideof the transparent resin 320 in order to easily position the lightreflecting member 321 within a metal mold when the light reflectingmember 321 is inserted within the transparent resin 320.

The light emitter 313 is mounted in the open hole 322 that is theelement mounting position of the optical module 312, the light emitter313 and the optical module 312 are housed within a housing 323, atransparent resin 324 is filled within the housing 323 to be filled in aspacing between an inner wall of the open hole 322 of the optical module312 and the light emitter 313, thereby constructing the light emissionsource 311 in an integrated fashion.

The light emitted from the LED chip 316 of the light emitter 313 to afront is emitted forward from the light emitter 313 as shown in FIG. 57at (a).

The light emitted from the LED chip 316 in a diagonal direction appearsfrom a side of the light emitter 313 to enter into the optical module312 through the open hole 322, and is totally reflected by a totalreflection region (resin boundary surface) 325 having a planar shape togo to the light reflecting member 321, and reflected by the lightreflecting member 321 to be emitted forward from the total reflectionregion 325 of the transparent resin 320.

According to this light emission source 311, the light emitted from theLED chip 316 in a diagonal direction or a transverse direction isreflected by the total reflection region 325 and the light reflectingmember 321 to be emitted forward, thereby increasing the emission angleof usable light, viz., an angle of field α and performing more brightlight distribution. Moreover, the optical module 312 is disposed nearthe light emitter 313, and the light emitted from the light emitter 313is reflected by the total reflection region 325 and the light reflectingmember 321 to be emitted forward, so that the optical system is notspatially large and the light emission source 311 itself can beminiaturized. Further, the emission direction of the light can be freelydesigned by means of the configuration of light reflecting member 321.

In this light emission source 311, the optical module 312 and the lightemitter 313 are different separated components, so that they areindividually quality-controlled and the defective factor of the lightemission source 311 can be reduced.

Thirty-Fourth Embodiment

FIG. 58 shows a sectional view of a light emission source 326 in which alight emitter 313 is mounted in an optical module 327 according to athirty-fourth embodiment of this invention. The light emitter 313 in acannonball shape is inserted within an open hole 322 of the opticalmodule 327 in a ring shape, and a transparent resin is filled between aninternal circumference face of the optical module 327 and the lightemitter 313 to unit with the optical module 312 and the light emitter313 as a single unit. As thus described, when a transparent resin havinga same index of refraction as that of the mold resin 319 and thetransparent resin 320 is filled between the optical module 312 and thelight emitter 313, loss of light by Fresnel loss or the like can bereduced.

The light emission source 326 can be miniaturized in comparison with thelight emission source 311 of the thirty-third embodiment because thehousing 323 can be omitted in this embodiment.

Thirty-Fifth Embodiment

FIG. 59 shows a sectional view of a light emission source 328 in which alight emitter 329 of a heat dissipation type is mounted in an opticalmodule 327 according to a thirty-fifth embodiment of this invention. Thelight emitter 329 of the heat dissipation type includes an LED chip 316mounted on a high heat sink portion 330 having a high thermalconductivity, and a transparent mold resin 332 covering an outercircumference face and a top face of the heat sink portion 330. In orderto enhance a heat dissipation nature of the heat sink portion 330, thereis disposed a recess 331 in a lower portion of the heat sink part 330for increasing the radiating area. In the light emitter 329 of this heatdissipation type, a convex lens-shaped optical lens division 333 isdisposed in a central part of the mold resin 332 opposing to the LEDchip 316.

In the light emitter 329 of this type, only the optical lens division333 is inserted in an open hole 322 of the optical module 327 to beassembled, while there is provided a small clearance ε between a lowerwall of the optical module 327 and a peripheral wall of the optical lensdivision 333.

By combining the light emitter 329 of such a heat dissipation type withthe optical module 327, more bright light distribution can be performedwithout losing the heat dissipation nature.

Thirty-Sixth Embodiment

FIG. 60 is a sectional view of a light emission source 341 in which thatan optical module 342 is mounted on a cannonball-shaped light emitter313 according to a thirty-sixth embodiment of this invention. In thislight emission source 341, an open hole 322 of the optical module 342does not open on the straight, but has a configuration along an externalform of the light emitter 313.

In this embodiment, when the light emitter 313 is inserted in the openhole 322 of the optical module 342, the light emitter 313 and theoptical module 342 are easy to come to agree with just, and dispersionof the insert depth of the light emitter 313 can be avoided.Accordingly, assembling is easy, thereby reducing its manufacturingcost. In this embodiment, the light emitter 313 can be inserted into theoptical module 342 by means of press fit.

Thirty-Seventh Embodiment

FIG. 61 shows a sectional view of a sectional view of a light emissionsource 343 in which a cannonball-shaped light emitter 313 is insertedwithin an optical module 344 according to a thirty-seventh embodiment ofthis invention. In this light emission source 343, a convex portion 345having a generally triangle shaped section is disposed on a top face ofthe optical module 344 to surround an open hole 322, and an incline faceof the convex portion 345 becomes high at its inner side.

In this embodiment, the convex portion 345 is disposed on the open hole322, and a surface of the convex portion 345 is inclined to protrude atits internal circumference side, total reflection of light is notproduced in the convex portion 345, and the light striking against theconvex portion 345 is easy to be emitted from the convex portion 345.Therefore, there is hard to appear any dark portion between the lightemitted from an optical lens portion (sphere portion) 346 of the lightemitter 313 and the light emitted from total reflection region 325 afterreflection by light reflecting member 321. This embodiment may employthe light emitter 329 of the heat dissipation type.

Thirty-Eighth Embodiment

FIG. 62 shows is a sectional view of a light emission source 347 inwhich a light emitter 313 is mounted on an optical module 348 accordingto a thirty-eighth embodiment of this invention. In this embodiment, anedge of an open hole 322 of the optical module 348 is diagonally beveledto provide a beveled portion 349, thereby preventing light from beingdirectly emitted without total reflection at an internal circumferenceportion of a total reflection region 325. Therefore, development ofstray light in the internal circumference portion of the totalreflection region 325 can be prevented. If desired, this embodiment mayemploy a light emitter of a heat dissipation type.

Thirty-Ninth Embodiment

FIG. 63 shows a sectional view of a light emission source 350 in which alight emitter 352 of a cannonball type is mounted in an optical module351 according to a thirty-ninth embodiment of this invention. In thisembodiment, a positioning portion 353 of a concave shape is disposed atan internal circumference of an open hole 322 of the optical module 351,and a positioning portion 354 in a convex shape is disposed at anoutside circumference of a rear end of mold resin 319 of the lightemitter 352.

Therefore, when the optical module 351 and the light emitter 352 areassembled, the positioning portions 353 and 354 are engaged each other,whereby optical axes of the optical module 31 and the light emitter 352can be adjusted each other and the insert depth to the open hole 322 ofthe light emitter 352 can be constant. Accordingly, assembling the lightemission source 350 becomes easy, and the assembly accuracy of the lightemission source 350 is improved.

Fortieth Embodiment

FIG. 64 shows a fortieth embodiment of this invention. In this lightemission source 355, an optical module 327 of a ring shape is disposedon a circuit board 356 mounted by an LED chip 316, wherein the lightemitted forwardly from the LED chip 316 to an air is directly emittedforward, the light emitted from LED chip 316 in a transverse directionenters into a transparent resin 320 through an internal circumferenceface of the optical module 327 to be totally reflected by a totalreflection region 325, and the totally reflected light is furtherreflected by alight reflecting member 321 to be emitted forward from thetotal reflection region 325.

In this light emission source 355, the LED chip 316 is not covered withany resin. Accordingly, when the light emitted from the LED chip 316 ina transverse direction penetrates into transparent resin 320 of theoptical module 327 through the internal circumference face, the beam oflight is refracted by a relatively large angle β. When light beamsemitted in a same direction are compared each other, light is moreeasily spread outwardly in comparison with the LED chip 316 sealed by aresin (such as mold resin 319), so that a large size light emissionsource can be performed by increasing the light emission area of thelight emission source 355.

Forty-First Embodiment

FIG. 65 shows a sectional view of a light emission source 357 in whichan optical module 358 is mounted on a cannonball-shaped light emitter313 according to a forty-first embodiment of this invention. In theoptical module 358 employed in the light emission source 357, a front oflight emitter 313 is covered with a transparent resin 320. In a frontwall of the transparent resin 320 (resin boundary surface), a regionconfronting with a front of the light emitter 313 is composed of a lensportion 359 in a convex surface shape, and a peripheral region of thelens portion 359 is composed of a flat total reflection region 325. Arear wall of the lens portion 359 is formed to be a concave portion 360(element mounting location) having a concave configuration just fittedby the light emitter 313.

According to this light emission source 357, the light emitted forwardfrom an LED chip 316 enters into the transparent resin 320 of theoptical module 358, and is focused by a lens function when it is emittedfrom the optical lens portion 359 of the optical module 358. The lightemitted from LED chip in a transverse direction is totally reflected bytotal reflection region 325 of optical module 358 to be directed to thelight reflecting member 321, and the light reflected by the lightreflecting member 321 is emitted forward through the total reflectionregion 325 of the transparent resin 320. Therefore, the light emittedfrom total reflection region 325 also is focused by an optical functionby the light reflecting member 321. Accordingly, light emitted from theLED chip 316 in any directions is focused by optical functions, and anemission area of the light emission source 357 can be increased.

When the configuration of a front of the light emitter 313 and theconfiguration of a concave portion 360 of the optical module 358 areformed to be hemispheric, the light loss caused by covering the opticalmodule 358 on the light emitter 313 consists of only loss when the lightenters into the optical module 358 from the light emitter 313, Fresnelloss when the light is emitted from the optical module 358, and a littleanti-loss in the light reflecting member 321, so that about 90% of thelight emitted from the LED chip 316 is efficiently emitted from thelight emission source 357 to external.

Thus, there is provided the construction the light emitter 313 fits withthe concave portion 360 of the optical module 358, so that positioningbecomes easy when the light emitter 313 is mounted on the optical module358. Because of easy positioning, the optical module 358 can be easilydetached from the light emitter 313, and a desired optical module can bechosen by preparing plural kinds of optical modules each having adifferent angle of beam spread and light distribution characteristics.

FIG. 66 at (a) to (c) is a schematic diagram a manufacturing process ofthe above-described light emission source 357. As shown in FIG. 66 at(a), a cavity 362 for molding an external configuration of the opticalmodule 358 and a concave portion 363 for molding the lens portion 359are formed in a molding metal mold 361. The light reflecting member 321is put reversely within the cavity 362 to position an edge of the lightreflecting member 321 with the cavity 362. Next the light emitter 313 isput within the cavity 362 so as to be located within an opening in thecenter of the light reflecting member 321 and held in space. With thiscondition, transparent resin 320 is injected within the cavity 362 to behardened as shown in FIG. 66 at (b) for molding optical module 358together with the light emitter 313 as a single unit. As shown in FIG.66 at (c), it is detached from the cavity 362 of the molding metal mold361 to provide the above-describe light emission source 357.

In thus produced light emission source 357, any air space is notproduced between the light emitter 313 and the optical module 358, andlight is hard to be reflected by air space produced between the lightemitter 313 and the optical module 358, thereby improving the opticalcoupling efficiency between the light emitter 313 and the optical module358. According to thus manufacturing process, the manufacturing processof the optical module 358 and the assembly process of the optical module358 and the light emitter 313 are executed at one time, whereby thewhole manufacturing process is streamlined. As a result a wholemanufacturing cost is reduced, and the accuracy of a positionalrelationship between the light emitter 313 and the optical module 358can be ensured.

The configuration in which a front face of the light emitter is coveredwith the optical lens portion 359 can be realized even if light emitter329 of a heat dissipation type is employed as shown in FIG. 67.

Forty-Second Embodiment

FIG. 68 shows a forty-second embodiment of this invention. An opticalmodule 358 employed in a light emission source 364 of this embodiment isdifferent from the optical module 358 shown in FIG. 65 because a frontwall of a transparent resin 320 of the optical module 365 is formed tobe flat and a portion confronting with a front face of a light emitter313 becomes a flat wall 366 including a total reflection region 325.

In this embodiment, the front face of the optical module 365 is notprotruded, thereby reducing the dimensions of light emission source 364.A disadvantage such that foreign matter of dust catches a projection ofthe front wall (lens portion 359) to be stuck to the optical module 365can be avoided.

In addition, such a configuration can be employed in a light emitter andan LED chip, which are of a heat dissipation type.

Forty-Third Embodiment

FIG. 69 shows a light emission source 367 according to a forty-thirdembodiment of this invention, in which the same optical module 358 asthat of FIG. 65 is employed to cover an LED chip 316 mounted on acircuit board 356. Though the light emission source 367 has aconstruction similar to the light emission source 355 of the fortiethembodiment (FIG. 64), the LED chip 316 of this light emission source 367is housed within a concave portion 360 of the optical module 358 and iscovered with the optical module 358, thereby increasing durability ofthe LED chip 316 and strengthening water resistance against a drop ofwater. In this light emission source 367, the light emitted forward fromthe LED chip 316 can be focused by lens portion 359. The concave portion360 is formed to have a hemisphere face having a center at a lightemission point of the LED chip 316, so that the light emitted from theLED chip 316 is hard to be reflected by a boundary surface of theconcave portion 360 and loss of light can be decreased.

A light emission source 368 shown in FIG. 70 is a modification of theabove-described light emission source 367, in which a recess 369 isformed at a central portion of a front of optical module 358, and a lensportion 359 is disposed within the recess 369 not to protrude from thefront of the optical module 358. According to this modified lightemission source 368, any prominence does not appear on a front wall ofthe optical module 358, thereby thinning the light emission source 368.

A light emission source 370 shown in FIG. 71 is a modification of theabove-described light emission source 367, in which a recessed portion360 in a rectangular parallelepiped shape is formed along theconfiguration of LED chip 316 to accommodate the LED chip 316.Therefore, positioning of the optical module 358 can be easily performedby applying the recessed portion 360 to the LED chip 316 to be mountedthereon.

Forty-Fourth Embodiment

FIG. 72 shows a sectional view of a light emission source 373 accordingto a forty-fourth embodiment of this invention. In an optical module 374employed in the this light emission source 373, a light reflectingmember 321 is not buried in a transparent resin 320 which is disposed ona front face of the light reflecting member 321, a rear wall of thelight reflecting member 321 made of metal is exposed. Since the rearwall of the light reflecting member 321 comes into direct contact with afresh air, it is easy to come to externally radiate heat occurring whenthe light emission source 373 emits light. Accordingly, temperature riseof an LED chip 316 is controlled to small, thereby applying a largercurrent to the LED chip 316 to increase the emission intensity in thelight emission source 373.

In addition, a leg 375 is disposed on the rear wall of the lightreflecting member 321 in order to stabilize the optical module 374 on acircuit board 356.

This light emission source 373 can be applied to a high mount stop lampof an automobile or a road traffic light machine which requiresbrightness, and such an application can be performed by a little numberof light emission sources.

Forty-Fifth Embodiment

FIG. 73 shows a sectional view of a light receiver 376 according to aforty-fifth embodiment of this invention, in which an optical module 358is disposed on a circuit board 356 to cover a photo detector 377 of aphoto diode mounted on the circuit board 356. In FIG. 73, the opticalmodule 358 employs the same as employed in the light emission source 367of FIG. 69, but an optical module having a different construction may beemployed if desired.

In this light receiver 376, the light striking against an optical lensportion 359 is directly focused on the photo detector 377 by the opticallens portion 359. On the other hand, the light striking against a resinboundary surface (total reflection region 325) outside the optical lensportion 359 is reflected by light reflecting member 321 through thetotal reflection region 325. The light reflected by the light reflectingmember 321 and reaching the total reflection region 325 again is totallyreflected by the total reflection region 325 to be focused on the photodetector 377.

Therefore, according to the combination of the optical module 358 andthe photo detector 377, the optical module 358 serves as a large opticallens so that large light receiving area is provided. In addition, evenif the light receiving area is widened by enlarging the optical module358 and make wide, the light receiver 376 can be avoided from alarge-scale receiver employing a conventional optical lens, and canbecome thin.

Forty-Sixth Embodiment

FIG. 74 shows a sectional view of a light receiver 378 according to aforty-sixth embodiment of this invention. In an optical module 379employed in the light receiver 378, cut portion 380 of a ring shape isformed at a stem (outer circumferential portion) of an optical lensportion 359 to incline at an angle y to the optical axis direction. Theangle y is a critical angle of total reflection in a total reflectionregion 325 of the light directed from a transparent rsin 320 to thetotal reflection region 325.

By arranging the cut portion 380, the optical lens portion 359 can beenlarged while the area where the light reflected by the lightreflecting member 321 is totally reflected is enlarged to a limitation,whereby the light requirements in the photo detector 377 is increasedand the light focus efficiency is improved. Design flexibility of thelight receiver 378 is increased by enlarging the spacing between theoptical lens portion 359 and the photo detector 377.

The optical module 379 having thus construction can be applied to alight emission source, if desired.

Forty-Seventy Embodiment

FIG. 75 show a sectional view of a light emission source 381 accordingto a forty-seventy embodiment of this invention, which is a combinationof a flat package-shaped light emitter 382 and-an optical module 383.The flat package-shaped light emitter 382 includes a mold resin 319having a flat-shaped front face (face in a light emission direction froman LED chip 316) flat-shaped. The optical module 383 includes aconfiguration similar to the optical module 358 employed in the lightemission source 367 of FIG. 69, but is different from the same becauseit does not have the recess portion 360. The optical module 383 at arear wall thereof is tightly contacted with a front wall of the moldresin 319 of the light emitter 382 to be bonded with transparentadhesives, and mounted on the light emitter 382. The light in the lightemission source 381 takes same light paths as the paths described above.

When thus flat-shaped light emission source 381 is used in an opticalsensor, the detection distance becomes longer, and the detectionaccuracy also becomes higher than a conventional optical sensor, wherebythe optical distance can be shortened and the optical sensor can bereduced in dimensions.

FIG. 76 shows a modification of the light emission source 384 in whichan optical module 385 mounted on a front wall of a light emitter 382 ofa flat package type is designed so that an optical lens portion 359 isnot sprung by engagement with a recessed portion 369 at a periphery of athe lens portion 359, whereby the light emission source 384 can be thin.

The light emission source 386 shown in FIG. 77 is another modification,in which a recess portion 388 in a circular cone shape is formed at afront central part of an optical module 387 mounted on a front wall oflight emitter 382 in a flat package shape. This recess portion accordswith an optical axis of LED chip 316, so that the light emitted forwardfrom the LED chip 316 can be totally reflected, whereby quantity oflight of the light which is emitted forward on straight from the LEDchip 316 can be reduced.

A light emission source 389 shown in FIG. 78 is still anothermodification, in which a shallow sphere-shaped recess portion 391 isformed at a front central part of an optical module 390. This lightemission source 389 can control distribution of light quantity of thelight emitted from a front wall of the optical module 390 by means ofthe recess portion 391.

A light emission source 392 shown in FIG. 79 is still anothermodification, in which a whole front wall of an optical module 390 isformed to be flat.

Forty-Eighth Embodiment

FIG. 80 shows a sectional view of a light emission source 393 accordingto a forty-eighth embodiment of this invention, in which a guidingportion 395 having a hook-shaped section is disposed on a rear wall ofan optical module 394 so as to catch a mold resin 319 of a light emitter382 of a flat package type.

If this guiding portion 395 is designed to catch a pair of sides of themold resin 319, the optical module 394 can be engaged with the moldresin 319 of the light emitter 382 by the guiding portion 395 as it isslid from the side.

If the optical module 394 is molded together with the light emitter 382as a single unit, the guiding portion 395 may be designed to catch foursides of the mold resin 319.

Forty-Ninth Embodiment

FIG. 81 is a view explaining a process for simultaneously producing aplurality of light emission sources. FIG. 81 at (a) shows light emissionsources 392 before they are separated individually from lead frame 391.The lead frame 391 includes leads 314 and 317 and stems made by means ofa punch processing, and LED chips are mounted in connection with thelead frame 391 to be molded with a mold resin 319 for providing lightemitters 392. In order to obtain each light emitter 392, each lightemitter 392 is separated from the lead frame 392. In this embodiment,however, each light emitter 392 connected with the lead frame 391 ismounted by optical module 393.

In the condition where each light emitter 392 is connected with the leadframe 391, each spacing between light emitters 392 is arranged to beconstant, whereby a plurality of optical modules 393 can besimultaneously mounted on the respective light emitters 392.Accordingly, light emitters 392 and optical modules 393 can be assembledby a lead frame basis with a high accuracy and a little dispersion inmanufacturing, and light emission sources can be assembled accuratelyand effectively. On the other hand, when the light emitters 391 arefixed to the lead frame 391, each spacing between the light emitters 391is limited, so that there might happen a case such that the spacing isinsufficient. In such a case, both edges of each optical module 393 arecut off to be ellipse-shaped, and a minor axis direction of each opticalmodule 393 has only to be adjusted to the arrangement direction of lightemitters 392 as shown in FIG. 81 at (b). Accordingly, area of eachoptical module 393 can be enlarged without being limited by spacing oflight emitters 392, and the light emission source having a large areacan be produced.

Fiftieth Embodiment

FIGS. 82 and 83 are perspective and sectional views of a light emissionsource array 400 according to a fiftieth embodiment of this invention. Aplurality of LED chips 316 are arranged at predetermined intervals on acircuit board 356 disposed on a pedestal base 401, and an optical modulearray 403 is put thereon. In the optical module array 403, there aredisposed lens portions 359 and light reflecting members 321 at the sameintervals as those of the LED chips 316. Thus, the respective lightemission sources 402 are arranged at the predetermined intervals in thelight emission source array 400, and designed to be individuallyenergized.

FIG. 84 shows a modification of the light emission source array, inwhich light emitters 405 each having a cannonball configuration areemployed. In this modified light emission source array 404, the lightemitters 405 are mounted on a circuit board 4 o 6 for a predeterminedpitch, and an optical module array 407 having openings in locationscorresponding to the respective light emitters 405 is put on the circuitboard 406. A light reflecting member 321 is disposed on the opticalmodule array 407 to surround each opening.

In these light emission source arrays 404 and 404, the respective lightemission sources arranged on a face emit light, which may be used as alight emission display unit.

In order to produce the light emission source array, the respectivelight emission sources may be arranged on the circuit board, in whichthey may be arranged in a honeycomb fashion by configuring each lightemission source 408 in a round shape as shown in FIG. 85 or in a hexagonshape as shown in FIG. 86. If desired, each light emission source 408may be formed in a rectangular shape, and arranged as shown in FIG. 87.

In addition, light emission sources 408 each having an ellipse shape maybe arranged in a major axis direction as shown in FIG. 88. Thus onedimension light emission source array may be used as a high mount stoplamp for a vehicle.

Fifty-First Embodiment

FIG. 89 is a sectional view showing a configuration of a light emissionsource 91 according to a thirty-third embodiment. In this light emissionsource 91, a stem 15 is disposed on a leading edge of a lead frame 17, alight emitter 12 such as an LED chip is die-bonded on the stem 15, andanother lead frame 14 is bonded with the light emitter 12 by means of abonding wire 16. A light reflecting portion 20 is molded aspherical by ametal plate, a specular working is applied to an inner wall of the metalplate by means of metal plating or etching, and an opening 20 a isdisposed in a generally central portion.

Leading edges of the lead frame 17 mounted by the light emitter 12 andthe lead frame 14 are passed in the opening 20 a of the light reflectingportion 20 to be sealed together with the light reflecting portion 20within a mold resin 13 made of a transparent resin having a highrefractive index. A total reflection region 19 is formed on a front wallof the mold resin 13, and a direct emission region 18 in a convexlens-shape is formed in a generally central portion thereof.

When the light emission source 91 is turned on, the light directlystriking against the direct emission region 18 in the light emitted fromthe light emitter 12 is focused by the direct emission region 18 to beemitted forward. The light directly striking against the totalreflection region 19 around the direct emission region 18 among thelight emitted from the light emitter 12 is totally reflected backward bythe total reflection region 19, further reflected by the lightreflecting portion 20 located at the backward of the total reflectionregion 19 to be squeezed so that the directional pattern becomes small(preferably, approximately paralleled light), and emitted forwardthrough the total reflection region 19. The light emitted in a directionat a large angle to the optical axis direction of the light emitter 12can be emitted forward, thereby greatly improving the use efficiency oflight. In addition, light can be emitted uniformly in a front of thelight emitter 12.

Furthermore, in this light emission source 91, a front of the mold resin13 (total reflection region 19) is inclined by φ against plane Eperpendicular to an optical axis of the light emitter 12. The directemission region 18 includes an aspherical lens, and an optical axis(center) F of the direct emission region 18 is shifted toward a tiltdirection of the total reflection region 19 (upward direction in FIG.89) than a geometrical center G of the total reflection region 19. Theoptical axis of the light emitter 12 is further shifted in the tiltdirection of the total reflection region 19 than optical axis F of thedirect emission region 18.

A curved shape of the light reflecting portion 20 is depicted by oneaspheric surface expression, and the light reflecting portion 20 has anasymmetry configuration which seems to be made by a portion shifted fromits center. The configuration of this light reflecting portion 20 willbe explained in detail referring to FIG. 90. In FIG. 90 at (a) and (b),a curved surface plate 92 shown in two-dotted lines includes a curvedsurface expressed by an aspheric surface expression having H as arotation symmetry shaft. The light reflecting portion 20 is cut by awall inclining a edge of the curved surface plate 92 by the angle φ in aJ direction. An opening 20 a of the light-reflecting portion 20 isformed in a round shape, and its center K is located in medium with arotation symmetry shaft H of curved surface plate 92 and a center G ofthe light reflecting portion 20. In addition, the center K of theopening 20 a almost accords with the optical axis the direct emissionregion 18. Both side edges 93 of light reflecting portion 20 are cutoff, so that the configuration of the light emission source 91 viewedfrom its front becomes a straw bag pattern cutting both side faces. Thisis because the light reflecting portion 20 is designed not to rotate ina metal mold molding on molding and not to be shifted about its locationby giving directivity to the light reflection portion which is not inrotation symmetry.

The configuration of the light emission source 91 viewed from its frontface is not limited to the straw bag pattern shown in FIG. 107, but maybe a round shape partially cut off as shown in FIG. 108, rectangle asshown in FIG. 109, or elliptic as shown in FIG. 110.

The optical axis of the light emitter 12 comes off from the center G ofthe light reflecting portion 20, and tilts to the gradient direction ofthe total reflection region 19.

In this light emission source 91, the total reflection region 19 and thelight reflecting portion 20 are slantly positioned as described above.As shown in FIG. 91, when the total reflection region 19 is installed toface to a slant upward direction and disturbance light such as morningsun or afternoon sun enters from a slant upward position, the lightreflected by the total reflection region 19 and the light reflectingportion 20 returns to its original slant upward direction and does notreach ground. Accordingly, this embodiment can avoid inconvenience suchthat the light emission source 91 seems to illuminate by means ofreflection light when it is turned off.

The light emitter 12 is shifted upward from the optical axis F of thedirect emission region 18, the light emitted from the light emitter 12and passing through the direct emission region 18 is emitted to adownward area which is different from the light reflected by the totalreflection region 19 and the light reflecting portion 20. The lightreflecting portion 20 has the asymmetry configuration, and the lightemitter 12 is shifted upward from the center of the light reflectingportion 20, so that the light, which is emitted from the light emitter12, totally reflected by the total reflection region 19, and furtherreflected by the light reflecting portion 20 to be emitted through thetotal reflection region 19, is emitted to a downward area which isdifferent from the reflection light in the total reflection region 19and the light reflecting portion 20. Accordingly, the light emitted fromthe light emission source 91 can be surely watched from ground withoutprevention by any disturbance light, and it can be clearly determinedwhether the light emission source 91 illuminates or not.

FIG. 92 shows an example of light distribution characteristic of thelight emitted by the light emission source 91. This light distributioncharacteristic has a gradient ε downwardly against the optical axis oflight emitter 12 or the medial axis of light emission source 91 to thelower part, and an asymmetry light distribution characteristic which isdistributed in a narrow spectrum to tilt direction (upward) of the totalreflection region 19 and a wide spectrum in the opposite side (downward)

According to such light distribution characteristic, when this lightemission source 91 is used for a signal, it can be watched brightly whenit is watched from far away but cannot be seen when it is looked up fromthe neighborhood, thereby realizing an ideal illumination demanded inthe signal.

In this light emission source 91, the direct emission region 18 isformed to be the aspherical lens and the light reflecting portion 20 isexpressed by the aspheric surface expression, so that the design oflight emission source 91 is eased.

As shown in FIG. 89, an outer circumferential edge of the lightreflecting portion 20 is located in a beveling potion 25 formed at afront circumference portion of mold resin 13. When the mold resin 13 ismolded, the outer circumferential edge of light reflecting portion 20abuts on an inside wall of the cavity of the molding metal mold toposition the light reflecting portion 20, and the resin flows throughthe opening 20 a of the light reflecting portion 20 so that the lightreflecting portion 20 can be easily insert-molded.

The direct emission region 18 is not limited to the aspherical lens, butmay be a spherical lens if desired.

Fifty-Second Embodiment

FIGS. 93 and 94 show front and sectional views of a signal 101 employinglight emission sources 91 as described above according to athirty-fourth embodiment.

The signal 101 is arranged by signal lamps 102R, 102Y and 102G for red,yellow and green colors, and its upper portion is covered with a hood103. As shown in FIG. 95, in each of the signal lamps 102R, 1021Y and102G, many light emission sources 91 of the corresponding light emissioncolor are mounted on a substrate 104 along a direction to be housedwithin a housing a front of which is covered with a milk-white or asemitransparent cover 106.

FIG. 97 is a sectional view showing a configuration of a signal lampemploying conventional LEDs 107 for comparison. In the conventional LED107, light is emitted forward on straight, so that the substrate 104 hasto be diagonally put within the housing 105 as shown in FIG. 97 in orderto put the substrate 104 mounted by LEDs 107 within the signal lamp toemit light downwardly. Therefore, the construction for installing thesubstrate 104 within the housing 105 of the signal lamp becomescomplicate. The thickness of the signal lamp also becomes thick becausethe substrate 104 has to be diagonally installed.

According to the signal 101 according to this invention, the lightemission sources 91 themselves can emit light in a downward diagonaldirection as shown in FIG. 96, and the substrate 104 can be installed inparallel with the housing 105 as shown in FIG. 95, thereby thinning thethickness of the signal lamps 102R, 102Y and 102G. The construction forinstalling the substrate 104 within each of the signal lamps 102R, 102Yand 102G becomes simple. The emission light is effectively distributedin an irradiation technical standard field of signal where upward is notnecessary to be irradiated, thereby realizing signal 101 employing thelight emission source 91 having a high luminous efficiency. In addition,any light reflected back with the light emission sources 91 are notreflected back downward, the visual performance about the signal lamps102R, 102Y, and 102G is improved.

In order to illuminate non-white light such as red, green and blue likelamps for the signal 101, there may be proposals of a light emissionsource which seals light emitters 12, such as a red light LED, a greenlight LED and a blue light LED, within transparent mold resins 13, orwhich seals light emitters 12 generating white light, such as a whitelight LED, within mold resins 13 consisting of a red transparent resin,a green transparent resin, and a blue transparent resin. According tothe former proposal, even if disturbance light such as sun light isreflected back toward ground by a surface of the mold resin 13 or thelight reflecting portion 20, the reflected light cannot be seen withcolor like when the light emission source is turned on, the reflectedlight is erroneously recognized as if the light emission source isturned on when it is actually turned off.

Fifty-Third Embodiment

FIG. 98 is a front view of a light emission display 111 supported by apole 11 according to a thirty-fifth embodiment, for example, for showinga traffic condition or a whether condition to drivers, in which lettersand illustrations are composed of light emission sources 91. FIGS. 99and 100 show front and sectional views of a light emission display unit112 providing the light emission display 111. In the light emissiondisplay unit 102, light emission sources 91 as described in thethirty-third embodiment are mounted on a substrate 113, and thesubstrate 113 is located between a base 114 and a cover 115 so as toexpose the respective light emission sources 91 from apertures of thecover 115. The light emission sources 91 are arranged on the substrate113 in a suitable pattern so as to emit suitable color light inaccordance with marks or letters to be displayed.

In the light emission display unit employing conventional LED 117, thelight from each LED 117 is emitted on the straight as shown in FIG. 101,so that the light emission display unit has to be declined downward forinstallation when it is installed on a wall or a top of a pole brace tobe easily watched from a lower position.

As shown in FIG. 100, in the light emission display 111 employing thelight emission sources 91 according to this invention, the lightemission sources 91 themselves can emit light in a diagonal-downwarddirection, so that light is emitted in the diagonal-downward directionwithout tilting the light emission display on installation and thedisplay can be watched from ground with ease. Accordingly, the lightemission display 111 can be easily installed, and become slim bythinning the same. Besides, because it is hard to become impossible tosee the light emission display due to the reflection of disturbancelight such as afternoon sun or morning sun, according to the lightemission display 111 employing the light emission sources 91 of thisinvention, the light emission display 111 a display of which can beclearly recognized is provided by employing the light emission sources91 having high luminous efficiency.

Fifty-Fourth Embodiment

FIG. 102 shows a sectional view of a configuration of a light emissionsource 121 according to a thirty-sixth embodiment, in which a mold resin13 seals a lead frame 17 at its top end die-bonded by a light emitter 12and a lead frame 14 wire-bonded with the light emitter 12 a, and inwhich a total reflection region 19 on a front flat wall of the moldresin 13 is formed on a plane perpendicular to an optical axis of thelight emitter 12. This light emission source 121 is installed so thatthe total reflection region 19 of the mold resin 13 is diagonally settoward a direction of disturbance light.

In this light emission source 121, even if disturbance light from a lowaltitude, such as the afternoon sun or the morning sun, strikes againstthe light emission source 121, the light reflected back with the totalreflection region 19 of the light emission source 121 is reflected backto the original direction (upward and diagonal) without arriving theground, and it can be avoided that the light emission source 121 seemsto be turned on when it is turned off.

On the other hand, if the angle of beam spread of light emitted by thelight emission source 121 is designed to be broad, the light emitteddownward can be viewed clearly from the lower part (ground), whereby thevisual recognition performance is not sacrificed. In order to easewatching the light emission source 121 from a lower part, the opticalaxis of the light emitter 12 in the mold resin 13 may be directed towardthe lower part so as to refract the light emitted from the light emitter12 with the total reflection region 19 for downward emission.

If desired, the mold resin 13 may form a direct emission region 18 inthe center of total reflection region 19 as shown in FIG. 103, which canprovide same effects as those of the light emission source 121 of FIG.102.

A light emission source 134 shown in FIG. 118 is a modification of thelight emission source 121 having a construction shown in FIG. 102, inwhich a light reflecting portion 20 having a symmetric configuration isdisposed at a rearward of the total reflection region 19, and the lighttotally reflected by the total reflection region 19 is reflected by thelight reflecting portion 20 to be emitted forward. A light emissionsource 135 shown in FIG. 119 is a modification of the light emissionsource 134 shown in FIG. 118 in which a direct emission region 18 isdisposed in the center of the total reflection region 19 (or amodification of the light emission source 122 as shown in FIG. 103 inwhich a light reflecting portion 20 having a symmetric configuration isdisposed).

Fifty-Fifth Embodiment

FIG. 104 is a sectional view of a configuration of a light emissionsource 123 according to a thirty-seventh embodiment, in which a moldresin 13 seals a lead frame 17 at its top end die-bonded by a lightemitter 12 and a lead frame 14 wire-bonded with the light emitter 12 aand a total reflection region 19 on a front wall of the mold resin 13 isdiagonally inclined against an optical axis of the light emitter 12.This light emission source 123 is generally horizontally installed sothat the total reflection region 19 (inclined plane) of the mold resin13 is set diagonally upward. A part of light emitted from the lightemitter 12 is refracted downward because the total reflection region 19is inclined. If desired, the optical axis of light emitter 12 may beinclined downward in order to emit more a lot of light to a diagonallower part.

In this light emission source 123, even if disturbance light from a lowaltitude, such as the afternoon sun or the morning sun, strikes againstthe light emission source 123, the light reflected back with the totalreflection region 19 of the light emission source 121 is reflected backto the original direction (upward and diagonal) without arriving theground, and it can be avoided that the light emission source 121 seemsto be turned on when it is turned off.

In addition, like the light emission source 124 as shown in FIG. 105, adirect emission region 18 may be disposed in the center of the totalreflection region 19 of the mold resin 13. This case can provide sameeffects as those of the light emission source 123 of FIG. 104.

Fifty-Sixth Embodiment

FIG. 106 is a sectional view of a configuration of a light emissionsource 125 according to a thirty-eighth embodiment, in which a moldresin 13 seals a lead frame 17 at its top end die-bonded by a lightemitter 12, a lead frame 14 wire-bonded with the light emitter 12, and alight reflecting portion 20, and in which a total reflection region 19on a front wall of the mold resin 13 is diagonally inclined. An outercircumferential edge of light reflecting portion 20 is cut diagonally,and the configuration of light reflecting portion 20 is asymmetric aboveand below. This embodiment includes the light emission source 91according to the thirty-third embodiment, wherein the direct emissionregion 18 is deleted.

This light emission source 125 is generally horizontally installed sothat the total reflection region 19 (inclined plane) of the mold resin13 is set diagonally upward. The light emitted from the light emitter 12and totally reflected by the total reflection region 19 is reflected bythe light reflecting portion 20, and refracted with the total reflectionregion 19 to be emitted downward. A part of light emitted forward fromthe light emitter 12 is refracted downward with the total reflectionregion 19. The optical axis of the light emitter 12 may be tilteddownward if desired.

In this light emission source 125, even if disturbance light from a lowaltitude, such as the afternoon sun or the morning sun, strikes againstthe light emission source 125, the light reflected back with the totalreflection region 19 of light emission source 125 is reflected back toits original direction (diagonally upward) without reaching the ground,so that the light emission source 125 can be avoided from seeming to beturned-on when it is turned-off.

In this light emission source 125, the light emitted from the lightemitter 12 to a peripheral direction is totally reflected by the totalreflection region 19, and further reflected by the light reflectingportion 20 to be emitted downward from the total reflection region 19,thereby improving the use efficiency of light.

Fifty-Seventh Embodiment

FIG. 111 is a sectional view of a configuration of a light emissionsource 126 according to a thirty-ninth embodiment. In this embodiment, atotal reflection region 19 on a front wall of a mold resin 13 isperpendicular to an optical axis of a light emitter 12, so that thelight emission source 126 itself is diagonally set not to reflectdisturbance light coming from a low altitude such as the afternoon sunor the morning sun to the lower part. On the other hand, a lightreflecting portion 20 in the mold resin 13 has a face which is expressedby asymmetry or different aspheric surface expressions in an upper halfand a lower half, whereby the light totally reflected by the totalreflection region 19 and reflected back with the light reflectingportion 20 is emitted downward from the total reflection region 19.

When thus constructed light emission source 126 is turned off and struckby disturbance light such as the afternoon sun or the morning sun, itcan be avoided that the disturbance light is reflected downward by thetotal reflection region 19 and the light reflecting portion 20 as if thelight emission source 126 is turned on.

In a light emission source 127 of an embodiment shown in FIG. 112, adirect emission region 18 has a profile that is asymmetry in an upperhalf and a lower half, whereby the light emitted from the directemission region 18 is emitted downward from the direct emission region18.

Fifty-Eighth Embodiment

FIG. 113 is a sectional view of a light emission source 128 according toa fortieth embodiment, in which a center of a direct emission region 18is located in the center of a total reflection region 19. When thecenter of direct emission region 18 is located in the center of totalreflection region 19 like this light emission source 128, light can beemitted diagonally downward from the direct emission region 18 by movingthe position of the light emitter 12 to be arranged in a proper position(higher position than the center of direct emission region 18).

Fifty-Ninth Embodiment

FIG. 114 is a sectional view of a configuration of alight emissionsource 129 according to a forty-first embodiment, in which a whole totalreflection region 19 is formed with a curved surface. The totalreflection region 19 is designed to totally reflect most of lightemitted from a light emitter 12, in which most of light emitted from thelight emitter 12 is totally reflected backward by the total reflectionregion 19 and further reflected by a light reflecting portion 20 to beemitted from the total reflection region 19. The configuration of thelight reflecting portion 20 or the position of the light emitter 126 aredesigned so that the light emitted from the total reflection region 19can be emitted downward. The total reflection region 19 is inclinedtoward an upward and diagonal direction, viz., a tangent plane 130 ofthe total reflection region 19 is slanted toward an upward and diagonaldirection.

Therefore, in this light emission source 129, most of disturbance lightsuch as the afternoon sun or the morning sun is reflected towardapproximately original direction and hard to reach a lower portion. Onthe other hand, light emitted from the light emitter 12 is reflectedseveral times to be emitted downward from the total reflection region19. Accordingly, when the light emission source 129 is employed as alight emission source for a signal, it can be avoided that the lightemission source 129 which is turned off is erroneously found as if it isturned on. When it is applied to a light emission display, a clear imagecan be watched without any slant installation.

The area of a front wall of the total reflection region of thisembodiment is large in dimensions, and strong light near the opticalaxis of the light emitter 12 in the light emitted by the light emitter12 with a Lambert distribution is reflected by the total reflectionregion 19 and the light reflecting portion 20 to be emitted from thelight emission source 129, thereby providing a light emission sourcehaving high luminous efficiency.

In FIG. 115, a light emission source 131 in whole is diagonally disposedtoward a diagonally upward direction instead of inclining the totalreflection region 19 (or tangent plane 130) toward the diagonally upwarddirection. Thus light emission source 131 can prevent disturbance lightfrom being reflected downward, and emission light from the lightemission source 131 can be emitted toward a diagonally downwarddirection.

Sixtieth Embodiment

FIG. 116 is sectional view of a light emission source 132 according to aforty-second embodiment, in which a direct emission region 18 isdisposed generally in the center of a front wall of a mold resin, and atotal reflection region 19 in a coned-shape is formed around the region18. A tangent plane 130 contacting an edge of the total reflectionregion 19 is inclined diagonally upward, and the angle of the totalreflection region 19 from the tangent plane 130 becomes ζ 1 in an uppersection of the total reflection region 19 and ζ 2 in a lower sectionthereof.

In the light emission source 132 according to this embodiment, the totalreflection region 19 is inclined diagonally upward so that disturbancelight such as the afternoon sun or the morning sun entering from a lowaltitude is reflected toward its original direction without reaching thelower part (ground). Light is emitted diagonally downward from the lightsource 132 by the position of light emitter 12 and the configuration oflight reflecting portion 20. Therefore, it can be avoided that the lightemission source 132 turning off seems to illuminate by reflection ofdisturbance light.

Instead of inclining the total reflection region 19 (or tangent plane130) diagonally upward, a light emission source 133 in whole is disposeddiagonally upward as shown in FIG. 117, in which disturbance light isprevented from downward reflection and the emission light from the lightsource 133 is diagonally downward.

Sixty-First Embodiment

FIG. 120 is a sectional view of a configuration of a light emissionsource 136 according to a forty-third embodiment, in which a totalreflection region 19 is disposed on a plane tilting from a planeperpendicular to an optical axis direction of a light emitter 12, adirect emission region 18 is disposed approximately in the center of theregion 19, and a light reflecting portion 20 having a symmetrical shapeis disposed rearward. The light emitter 12 is located in a positionshifting from the center of light reflecting portion 20 and directemission region 18, thereby emitting light diagonally downward.

Sixty-Second Embodiment

FIG. 121 at (a) and (b) shows front and side views of an outdoor typedisplay 141 according to a forty-fourth embodiment, in which lightemission sources 142 having a quadrangle external configuration viewedfrom its front according to this invention are arranged on a substrate143 in a matrix fashion. According to this outdoor type displayapparatus 141, the light emission sources 142 can be arranged withoutclearance, so that the display can have a light emission face withoutany clearance which is uniform on lighting and seen neatly.

The outdoor type display apparatus 141 is installed in a high locationto face a little diagonally upward direction because each front face ofthe light emission sources 142 is in parallel with the substrate 143.Even if the outdoor type display apparatus 141 is installed diagonallyupward, each light emission source 142 emits light diagonally downward,and the display can be watched clearly from a lower position.

Sixty-Third Embodiment

FIG. 123 at (a) to (c) shows one example of a manufacturing process fora light emission source according to forty-fifth embodiment. Though alight emission source is described in this embodiment, a light receivercan be applied to this embodiment. In FIG. 123, there is shown a metalmold 151 for manufacturing a light emission source, which is providedwith a cavity 152 for molding a mold resin 13. The cavity 152 at abottom wall thereof is provided with a pattern face 153 for forming atotal reflection region 19 and a pattern face 154 for forming a directemission region 18.

As shown in FIG. 123, light reflecting portion 20 is inserted within thecavity 152. Since the external diameter of the light reflecting portion20 is almost equal to the inside diameter of the cavity 152, the lightreflecting portion 20 can be positioned within the cavity 152 by puttingthe light reflecting portion 20 on the bottom wall of cavity 152.

In FIG. 123 at (b), there is shown a component including a light emitter12 die bonded on a stem 15 of a lead frame 17, and a lead frame 14connected with the light emitter 12 by a bonding wire 16, which isproduced in other process beforehand. As shown in FIG. 123 at (b), thecomponent is put within the cavity 152 with positioning the lightemitter 12 downward, and upper ends of the lead frames 14 and 17 aresupported to fix the light emitter 12 at a predetermined position withinthe cavity 152.

With this condition, a mold resin 13 is injected within the cavity 152to be inserted by the light emitter 12 and the light reflecting portion20 to mold a direct emission region 18 and a total reflection region 19as shown in FIG. 123 at (c). As the injected mold resin 13 is cooled andstiffened, it is taken out from the cavity 152 to produce the lightemission device.

According to this manufacturing process, light reflecting portion 20 canbe easily positioned, and mass production for the light emission sourcesor the light receivers can be performed.

Next, several applications of a light emission source according to thisinvention, such as a light emission source according to the embodimentsshown in FIGS. 3 to 21, will be described hereinafter.

Sixty-Forth Embodiment

FIG. 124 shows a light emission display unit 161 arranged by lightemission sources 162 depending on this invention as a forty-sixthembodiment. When light emission sources 163 of a cannonball type asshown in FIG. 125 at (a) are employed to provide such a display 161, thebeam profile is bright around its center but dark near its periphery(see FIG. 4 at (b)), so that its visual performance is not uniform. Whencannonball-shaped light emission sources 163 as shown in FIG. 125 at (b)are arranged, there appears clearance between the light emission sources163 to produce darkness, thereby decreasing its visual performance.

The light emission source 162 according to this invention, however, canhave a rectangular configuration as shown in FIG. 126, whereby plurallight emission sources 162 can be arranged without clearance as shown inFIG. 124 and darkness is avoided to appear between the sources 126, andits visual performance is improved. In addition, in the light emissionsource 162 according to this invention, uniform beam profile as shown inFIG. 4 at (a) can be provided by synthesizing light from direct emissionregion 18 in a lens shape and light from light reflecting portion 20.When pictorial image and letter is pictured as confluence of lightemission sources 162, light emission points are easy to be connectedeach other and satiny pictorial image and letter can be displayed.

As another application, there may be provided a full color lightemission display arranged by light emission sources respectivelyemploying red (R), green (G), and blue (B) as shown in FIG. 127.

When a multicolor light emission display (not shown in drawings) isarranged by light emission sources 36 as shown in FIG. 21, a displayhaving little color isolation can be provided.

Sixty-Fifth Embodiment

FIG. 128 shows an optical fiber coupler 164 employing a light emissionsource 162 according to this invention as a forty-seventh embodiment. Inthis optical fiber coupler 164, an optical lens 165 is interposedbetween light emission source 162 and an end surface of an optical fiber167, in which light emitted from the light emission source 162 isfocused by the optical lens 167 to the end surface of the optical fiber167 to be coupled with the optical fiber 167. The optical lens 165 hasdifferent optical lens constants at the points corresponding to directemission region 18 and total reflecting region 19 in the light emissionsource 162, and a complex configuration with two kinds of convex lenses166 a and 166 b. The light emitted from direct emission region 18 of thelight emission source 162 is coupled with the end surface of the opticalfiber 167 in a central part of the optical lens 165, and the lightemitted from the total reflection region 19 is coupled with the endsurface of optical fiber 167 by a circumscription part of the opticallens 165.

Thus, the light emitted from the direct emission region 18 in thecentral part and the light emitted from the total reflection region 19in the circumscription part can be efficiently focused on the endsurface of the optical fiber 167 by different lens parts, therebyimproving the fiber association efficiency important in the systememploying light emitting diodes.

Sixty-Sixth Embodiment

FIG. 129 shows a side view of a signal lamp 168 employing light emissionsources 162 according to this invention as a forty-eighth embodiment,which is composed of a red signal lamp arranged by light emission source162 of red light emission color, a green signal lamp arranged by lightemission source 162 of green light emission color, and an yellow signallamp arranged by light emission source 162 of yellow light emissioncolor. The signal lamp 168 is installed diagonally upward not to directthe reflection light of the afternoon sun by the signal lamp 168 to anyvehicles. Accordingly, hate for watching signal by the reflection lightof the afternoon sun considered to be a problem in the signal isresolved.

The light emission source 162 employs such a light source 34 or 35diagonally emitting light as shown in FIG. 19 or 20, and emits lighttoward a roadside diagonally downward. Thus, deterioration of the visualperformance by the afternoon sun is prevented, and the signal lamp 168is easy to be watched from a road. Luminous radiation to an upperdirection is uselessness according to the technical standard of signal,so that the emitted light is focused downward, thereby realizing a highbright signal lamp.

A conventionally used light emission source having a cannonballconfiguration is limited to a certain degree to provide an asymmetricalbeam profile due to design relying on a lens configuration. Accordingly,when a signal lamp employing the conventional light emission source isinstalled upward, it is hard to be watched from ground due to preventionagainst light reflection of the afternoon sun. According to thisinvention, however, the mirror configuration is designed to beasymmetrical, and position of a light emitter is shifted from itsoptical axis, thereby easily resolving it.

Sixty-Seventh Embodiment

FIG. 130 shows an advertisement signboard 170 employing a light emissionsource according to this invention as a forty-ninth embodiment. Theadvertisement signboard (illumination signboard) 170 installed on a wallof a building 169 as shown in FIG. 130 is designed to emit lightdownward so that the visual performance is good when it is viewed fromthe ground. When the advertisement signboard 170 is designed not to emitlight toward the wall of the building in a horizontal plane as shown inFIG. 131, higher brightness of the advertisement signboard can beperformed by decreasing useless light.

Sixty-Eighth Embodiment

FIG. 132 is a perspective view of a high mount strap lamp 171 employinglight emission sources 173 according to a fiftieth embodiment, in whicha plurality of light emission devices 173 each having about an ellipseshape as shown in FIG. 133 are aligned in a line and mounted on alaterally long substrate 174.

The light emission source 173 for the high mount strap lamp has a sameconstruction as that of the light emission source 24 as shown in FIGS. 8to 10, but a disc-shaped light reflecting portion 20 is inserted withina mold resin 13 by downwardly bending both ends thereof because thewhole configuration of the light emission source has a laterally longfront wall such as generally ellipse, oval or rectangle. The lightemission sources 173 are mounted on the substrate 174 so that theirmajor axis directions are parallel with a length direction of thesubstrate.

The high mount strap lamp 171 is installed in an inside of a rear window175 of a vehicle 172. When a driver of the vehicle 172 steps on a brakepedal, all light emission sources 173 illuminate at once to alarm itsfollowing vehicle.

When the high mount strap lamp 171 employs such laterally long lightemission sources 173, oblong light can be emitted with good efficiency.In addition, the number of necessary light emission sources 173 may bereduced by making each light emission source 173 laterally long, therebyreducing the manufacturing cost of the high mount strap lamp 171.

Several applications of a light emission source having major and minoraxial directions when it is viewed from its front, such as the lightemission source in the embodiments as shown in FIGS. 22 to 33 will bedescribed hereinafter.

Sixty-Ninth Embodiment

FIG. 134 is a perspective view of a high mount strap lamp 184 accordingto a fifty-first embodiment, in which light emission sources accordingto this invention are aligned in a line and mounted, and which isinstalled inside of a rear window 188 of a vehicle so as to illuminatewhen a driver steps a brake pedal of the vehicle. The light emissionsource composing the high mount strap lamp 184 may employ a lightemission source like each of the above-described embodiments, but thelight emission source 67 shown in FIG. 41 is preferred.

As shown in FIG. 137 at (a), a conventional high mount strap lamp 189generates laterally long light beams by arranging a plurality of lightemitting diodes 190 in a line and emitting light thorough a scatteringoptical lens 191 disposed on a front wall of the lamp. In theconventional high mount strap indicator 189, a single light emittingdiode 190 can emit light on a square region shown in FIG. 137 at (b),thereby requiring a lot of light emitting diodes 190.

As shown in FIG. 136 at (a), the high mount strap lamp 184 of thisinvention employs a light emission source 185 emitting beams having theratio of (major axial length) : (minor axial direction) =2 : 1 and aspreading optical lens 186 corresponding to a beam profile disposed infront of the source, so that one light emission source 185 can emitlight from two times of emission areas by the conventional lightemitting diode 190. Accordingly, the arrangement pitch of light emissionsources 185 can be a half of the arrangement pitch of the conventionallight emitting diodes 190.

The light emission source 185 of this invention can realize more thantwo times of the conventional efficiency of light use in comparison withthe conventional light emitting diodes 190. When the arrangement pitchis designed to be two times of the conventional light emitting diodes190, light power emitted by each light emission source 185 becomes twotimes, and the light power emitted from the high mount strap lamp 184becomes the same as a conventional lamp. According to the high mountstrap lamp 184 employing the light emission sources 185 of thisinvention, the number of light emission sources can be reduced to half,its assembling becomes easy by reducing the number of components number,and reduction in cost becomes possible largely.

Seventieth Embodiment

FIG. 138 is a perspective view of a display unit 201 employing lightemission sources according to a fifty-second embodiment. In the displayunit 201, a lot of light emission sources 202 are arranged in a matrixor honeycomb fashion, and each light emission source 202 is arranged sothat its major axis direction turns to a horizontal direction. ThoughFIG. 138 shows a stand shape, the unit may be installed in a wallhanging type or on an external wall of a house.

In the event of display unit installed in bearing height dimension oforder of a person, it is preferable that the display unit can be seenfrom various angles in a horizontal direction as an angle of beam spreadof the display unit. The display unit 201 employs the light emissionsources 202 each arranged directing its major axis direction in thehorizontal direction, and the light itself emitted form each lightemission source 202 has the directional pattern opened in a transversedirection as shown in FIG. 139, s 0 that the display unit 201 can have awide directional pattern in the transverse direction as shown in FIG.140. Thus, a display unit having a good visual effect can be produced.

Several applications when this invention is applied a light receiverwill be described hereinafter.

Seventy-First Embodiment

FIG. 141 is a schematic view showing a construction a photoelectronicsensor 211 to detect the presence of an object of a diffuse reflectiontype according to a fifty-third embodiment. The photoelectronic sensor211 includes a projector 212 employing a light emitting diode, a drivingcircuit 213 for driving the light emitting diode, a light receiver 214of this invention (for example, the light receiver shown in FIG. 30 or31), an amplifier circuit 215 for amplifying an output from the lightreceiver 214, and a processing circuit 216 for controlling the drivingcircuit 213 and receiving a light receive signal from the amplifiercircuit 215 to do distinction of the presence of the object.

As shown in FIG. 141, when there appears an object 217 in ahead ofphotoelectronic sensor 211 that diffuses and reflects light and thelight emitted from the projector 212 of the photoelectronic sensor 211strikes against a surface of the object 217, the reflection light in aregion shown by oblique lines in the light reflected by the surface ofobject 217 is received by the light receiver 214, whereby the presenceof the object is determinedly the processing circuit 216 and a detectionsignal is produced.

In this photoelectronic sensor 211, detection distance of object isdetermined by the minimum light requirement (S/N ratio) that candistinguish the reflection light from object 217 from an internal noiseof sensor. If light intensity emitted by the projector 212 is the same,the intensity of reflection light from object 217 does not change, butthe light receiving efficiency is improved and the light requirement isincreased by using the light receiver 214 of this invention, therebyproviding room in the detection. By employing this photoelectronicsensor 211, an object in a further distance can be detected and thelight requirement becomes big, thereby prolonging the detectiondistance. For example, the detection distance spreads in generally ° 2times when the light requirement doubles.

In order to get such an effect, a large optical lens is disposed infront of a conventional photoelectronic sensor, and it is necessary forcondensing the reflection light in the region marked by the obliquelines shown in FIG. 141 to be received by a small light receiver. Thephotoelectronic sensor 211 of this invention, however, can be realizedwithout employing lens, so that the light receiver 214 is thinned inthickness, the photoelectronic sensor 211 is miniaturized, and thenumber of components is reduced, thereby reducing variation of lightreceiving system and manufacturing cost of the photoelectronic sensor211.

This photoelectronic sensor is not limited to this reflection type, andsimilar effect can be performed in a transmission type photoelectronicsensor. The detection also is not limited to sensing the presence of anobject, but can be applied to detecting a distance (analog quantity) toan object.

Seventy-Second Embodiment

FIG. 142 is a sectional view of a road tack 221 according a fifty-fourthembodiment. Generally a road tack is buried in road in a safety zone orcrossover of road, but a conventional road tack has characteristics onlyreflecting back a headlight of motor.

The road tack 221 shown in FIG. 142 houses light emission sources 222 ofthis invention, light receivers 223 of this invention, a battery charger224, and a drive circuit 225, a surface of which is covered by atransparent cover 227. Solar light is received by the light receivers223 in the daytime to charge the battery charger 224, and the lightemission source 222 is activated by the drive circuit 225 by using anelectric power of the battery charger 224 in the nighttime.

According to this road tack 221, the battery charger 224 can effectivelycharged by employing the light receivers 223 of this invention in thedaytime. The light receiver 223 can be thinned in thickness, so that theroad tack 221 also becomes to thin and embedding in the road 226 iseased.

This embodiment is described about a road tack, but may be widelyapplied to a self light generator in which a light unit is activated inthe nighttime by using the electric energy charged in a battery chargerby a light receiver in the daytime, such as a delineator or a sight lineguidance light other than the road tack.

Seventy-Third Embodiment

An illuminated-type switch will be described hereinafter as anapplication of a light emission source employing an optical module. Asshown in FIG. 146, a conventional illuminated-type switch 241 includes aplurality of LEDs 245 installed within a recess 244 disposed in a lightemission unit 243 on a back side of a transparent or semitransparent cap242 which serves as a push switch, and a diffusing plate 246 above thesame. As the cap 242 is depressed and the switch is turned on, the LED245 is activated to illuminate the cap 242 in whole by the diffusingplate 246. In order to illuminate the cap 242 in whole in a large area,the illuminated-type switch 241 is necessary to have the plural LEDs 245and the diffusing plate 246, whereby the number of components becomeslarge, and the switch is costly, large power consumptive, and bulky.

FIG. 143 shows a schematic perspective view of an illuminated-typeswitch 231, FIG. 144 shows its perspective disassembled view, and FIG.145 shows a generally sectional view of the switch, according to afifty-fifth embodiment. In this illuminated-type switch 231, one lightemitter 12 is installed within a recess 233 disposed on an upper wall ofa light emission unit 232, and an optical module 72 as shown in FIG. 47is put to cover the light emitter 12. Above the recess 233, there isarranged a transparent or semitransparent cap 234 (a cut pattern may beformed in the rear face) which is elastically pushed upward by a spring(not shown) and held by a cap holder 235. The light emission unit 232 ismounted on a top wall of a switch body 236.

In this illuminated-type switch 231, when the cap 234 serving as a pushswitch is depressed to be turned on, the light emitted from the lightemitter 12 is spread over the optical module 72 by the optical module 72to radiate the cap 234 for illuminating the cap 234 in whole.

Therefore, according to such illuminated-type switch 231, the number ofcomponents and cost can be decreased, thereby reducing the powerconsumption in lighting, and enabling miniaturization.

In a self light generator, such as the solar cell (FIG. 33) or the roadtrack (FIG. 110), or a light emission source of FIG. 6, a conventionalphoto detector or a photoelectric transducer can be combined with theoptical module shown in FIGS. 46 to 49 and 50 to 56.

1-35. (canceled)
 36. An optical component comprising: a transparent bodyhaving a direct emission region, a total reflection region disposedaround said direct emission region, and a curved reflective surfacewhich faces said direct emission region and said total reflectionregion; and a recess provided on said curved reflective surface, whereinthe thickness of said transparent body is smaller than a diameter of anouter edge of said curved reflective surface, wherein a part of saidtotal reflection region in proximity of said direct emission region isinclined to a plane of the other parts of said total reflection region,wherein said curved reflective surface is covered with high reflectivematerial, wherein said direct emission region passes incident lightdirectly passing through said recess, and wherein said curved reflectivesurface indirectly receives light passing through said recess, and saidtotal reflection region reflects incident light directly passing throughsaid recess and passes the light reflected by said curved reflectivesurface through said total reflection region.
 37. An optical componentcomprising: a circuit board; a transparent body disposed on said circuitboard, wherein a front portion of the transparent body comprises adirect emission region and a total reflection region disposed aroundsaid direct emission region; a curved light reflecting portion having arecess at a center of said curved light reflecting portion and disposedon said circuit board to face said front portion; and a light-emittingelement mounted on said circuit board to face said direct emissionregion through said recess such that light from said light-emittingelement is indirectly incident on said curved light reflecting portion,wherein the size and shape of said curved light reflecting portion isselected such that a mirror focus of said light-emitting element withrespect to a plane including said total reflection region is defined asa focal point of said light reflecting portion, wherein a part of saidtotal reflection region in proximity of said direct emission region isinclined to a plane perpendicular to an optical axis of saidlight-emitting element, wherein said direct emission region passesincident light directly passing through said recess, and wherein saidcurved light reflecting portion indirectly receives light passingthrough said recess, and said total reflection region reflects incidentlight directly passing through said opening and passes the lightreflected by said curved light reflecting portion through said totalreflection region.